HomeMy WebLinkAbout2007-02-06; City Council; 18888; Establish Speed Limit - Melrose Drive12
CITY OF CARLSBAD - AGENDA BILL
AB# 18,888
MTG. 2/06/07
DEPT. ENG
ESTABLISH A PRIMA FACIE SPEED LIMIT
UPON MELROSE DRIVE FROM
PALOMAR AIRPORT ROAD TO THE NORTH CITY LIMIT
DEPT. HEAD ftf^
CITY ATTY. <^S^
CITY MGR. f u
RECOMMENDED ACTION:
Introduce Ordinance No. NS-832 to establish a prima facie 55 mile per hour speed limit
upon Melrose Drive from Palomar Airport Road to the north city limit.
ITEM EXPLANATION:
Melrose Drive is designated as a prime arterial roadway in the Circulation Element of the General
Plan. It is a six-lane, divided road and has a posted speed limit of 55 miles per hour south of Palomar
Airport Road established upon the results of an engineering and traffic survey.
The segment of Melrose Drive north of Palomar Airport Road opened to traffic on August 16, 2006.
It has a daily traffic volume of 21,000 vehicles and has no posted speed limit. The maximum speed
limit on said portion of Melrose Drive is 65 miles per hour. California Vehicle Code section 22358(a)
requires that 'Whenever a local authority determines upon the basis of an engineering and traffic
survey that the limit of 65 miles per hour is more than is reasonable or safe upon any portion of any
street other than a state highway where the limit of 65 miles per hour is applicable, the local authority
may by ordinance determine and declare a prima facie speed limit of 60, 55, 50, 45, 40, 35, 30, or
25 miles per hour, whichever is found most appropriate to facilitate the orderly movement of traffic and
is reasonable and safe, which declared prima facie limit shall be effective when appropriate signs
giving notice thereof are erected upon the street."
The California Legislature has clearly indicated its intent with respect to speed limits established on
the basis of an engineering and traffic survey and regarding speed traps. Vehicle Code section
40802(a)(2) defines a speed trap as "...that prima facie speed limit is not justified by an engineering
and traffic survey conducted within five years prior to the date of the alleged violation, and
enforcement of the speed limit involves the use of radar...."
A well known and widely read court case in California that was the subject of the speed trap law is
The People v. Judith Ann Goulet (1992) 13 CAL.APP.4TH SUPP. 1. The Appellant Department,
Superior Court, Ventura, found that in this case, the engineering and traffic survey did not justify the
prima facie speed limit and since radar was used in enforcement, a speed trap existed.
The conclusion of the court was that "Speed traps—reduced speed zones not justified by the
conditions—bring disrespect to law enforcement and the courts. We have discussed the requirements
and consequences at length because it must be clear to traffic engineers, local authorities, and law
enforcement officers that if a prima facie speed limit is set without being justified in fact by the
engineering and traffic survey, the speed limit cannot be enforced by any means involving the use of
radar. Local authorities must set prima facie speed limits carefully, as justified by appropriate factors,
to avoid making use of radar unavailable for speed enforcement."
FOR CITY CLERKS USE ONLY.
COUNCIL ACTION: APPROVED
DENIED
CONTINUED
WITHDRAWN
AMENDED
Efnn
n
D
CONTINUED TO DATE SPECIFIC
CONTINUED TO DATE UNKNOWN
RETURNED TO STAFF
OTHER - SEE MINUTES
nn
Dn
Page 2
In accordance with the requirements of Vehicle Code section 627 and the California Manual on
Uniform Traffic Control Devices (MUTCD), an engineering and traffic survey was prepared for the
subject portion of Melrose Drive. The survey took into account the prevailing speeds, accident history,
and highway and roadside conditions, among other factors. Also considered were the provisions of
Vehicle Code section 22358.5 that provides "It is the intent of the Legislature that physical conditions
such as width, curvature, grade and surface conditions, or any other condition readily apparent to the
driver, in the absence of other factors, would not require special downward speed zoning, as the basic
rule of section 22350 is sufficient regulation as to such conditions."
The results of the engineering and traffic survey were presented to the Traffic Safety Commission on
December 4, 2006. Three Carlsbad residents addressed the Commission and requested that a
45 mile per hour speed limit be established. In response to inquiry from one Commissioner,
Lt. Rawson from the Traffic Division of the Carlsbad Police Department, answered that a 45 mile per
hour speed limit upon this portion of Melrose Drive would be considered a speed trap by definition of
the Vehicle Code, and court rulings over the past several years, and would be unenforceable by the
Police Department.
Upon consideration of public testimony, results of the engineering and traffic survey, the
recommendation of the Traffic Safety Coordinating Committee (staff committee), and the testimony of
Lt. Rawson, the Commission recommend, by a 4-0 vote, that a prima facie 55 mile per hour speed
limit be established upon Melrose Drive from Palomar Airport Road to the north city limit.
ENVIRONMENTAL IMPACT:
The installation of an official traffic control device is a project that is a Class 1 categorical
exemption (minor alteration of existing structure or facility) and is, therefore, exempt from the
environmental review process under the provisions of the California Environmental Quality Act
(CEQA), Section 15301(c).
FISCAL IMPACT:
Installing two speed limit signs upon Melrose Drive will cost about $250.
EXHIBITS:
1. Location Map.
2. Ordinance No. NS-832 to establish a prima facie 55 mile per hour speed limit
upon Melrose Drive from Palomar Airport Road to the north city limit.
3. Redline/strikeout version of Ordinance No. NS-832 to establish a prima facie
55 mile per hour speed limit upon Melrose Drive from Palomar Airport Road to the north city
limit.
DEPARTMENT CONTACT: Robert T. Johnson, Jr., (760) 602-2752, biohn@ci.carlsbad.ca.us
LOCATION MAP
PROPOSED
SPEED ZONE
NOT TO SCALE
CITY OF CARLSBAD
LEGEND:
(j) TRAFFIC SIGNAL
PROJECT NAME PROPOSED SPEED ZONE
MELROSE DRIVE
PALOMAR AIRPORT ROAD TO NORTH CITY LIMIT
EXHIBIT
1
DRAWN BY: SCOTT EVANS, CARLSBAD ENGINEERING DEPT. 9/1/06 C:\JRAFFIC\SPEED ZONE\SPEED ZONE-MELROSE DRIVE NORTH.DWG
10
1
ORDINANCE NO. NS-832
2
AN ORDINANCE OF THE CITY COUNCIL OF THE CITY OF
3 CARLSBAD, CALIFORNIA, AMENDING TITLE 10, CHAPTER 10.44,
OF THE CARLSBAD MUNICIPAL CODE BY THE AMENDMENT OF
4 SECTION 10.44.240 TO ESTABLISH UPON MELROSE DRIVE A
PRIMA FACIE 55 MILE PER HOUR SPEED LIMIT FROM PALOMAR
5 AIRPORT ROAD TO THE NORTH CITY LIMIT.
6 The City Council of the City of Carlsbad, California, hereby ordains as follows:
7 SECTION 1: That Title 10, Chapter 10.44, of the Carlsbad Municipal Code is amended
g by the revision of Section 10.44.240 to read as follows:
"10.44.240 Melrose Drive.
Upon Melrose Drive from Rancho Santa Fe Road to the north city
limit, the prima facie speed limit shall be fifty-five miles per hour."
EFFECTIVE DATE: This ordinance shall be effective thirty (30) days after its adoption; and
12 the City Clerk shall certify the adoption of this ordinance and cause it to be published at least once in
13 a newspaper of general circulation in the City of Carlsbad within fifteen (15) days after its adoption.14 ///15 ///16 ///
17 ///18 ///19 ///
20 ///
21 "
22
23
24
25
26
27
28
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
INTRODUCED AND FIRST READ at a regular meeting of the Carlsbad City Council on
the 6th day of February, 2007, and thereafter.
PASSED, APPROVED AND ADOPTED at a Regular Meeting of the City Council of the
City of Carlsbad on the day of, 2007, by the following vote:
AYES:
NOES:
ABSENT:
ABSTAIN:
APPROVED AS TO FORM AND LEGALITY
RONALD R. BALL, City Attorney
CLAUDE A LEWIS, Mayor
ATTEST:
LORRAINE M. WOOD, City Clerk
(SEAL)
2 ORDINANCE NO. NS-832
3 AN ORDINANCE OF THE CITY COUNCIL OF THE CITY OF
CARLSBAD, CALIFORNIA, AMENDING TITLE 10, CHAPTER 10.44,
4 OF THE CARLSBAD MUNICIPAL CODE BY THE AMENDMENT OF
SECTION 10.44.240 TO ESTABLISH UPON MELROSE DRIVE A
5 PRIMA FACIE 55 MILE PER HOUR SPEED LIMIT FROM PALOMAR
AIRPORT ROAD TO THE NORTH CITY LIMIT.
6
The City Council of the City of Carlsbad, California, hereby ordains as follows:
7
SECTION 1: That Title 10, Chapter 10.44, of the Carlsbad Municipal Code is amended
8
by the revision of Section 10.44.240 to read as follows:
9 "10.44.240 Melrose Drive.
Upon Melrose Drive from Rancho Santa Fe Road to its intersoction
11 with Palomar Airport Road the north city limit, the prima facie speed
limit shall be fifty-five miles per hour."
EFFECTIVE DATE: This ordinance shall be effective thirty (30) days after its adoption; and
13 the City Clerk shall certify the adoption of this ordinance and cause it to be published at least once in
14 a newspaper of general circulation in the City of Carlsbad within fifteen (15) days after its adoption.15 ///16 ///17 ///18 ///19 ///20 ///
21 "
22
23
24
25
26
27
28
U
5
6
7
8
9
10
day of
INTRODUCED AND FIRST READ at a Regular Meeting of the Carlsbad City Council on the
, 2007, and thereafter
PASSED AND ADOPTED at a Regular Meeting of the City Council of the City of Carlsbad,
California, on the day of.
AYES:
NOES:
ABSENT:
APPROVED AS TO FORM AND LEGALITY:
, 2007, by the following vote, to wit:
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
RONALD R. BALL, City Attorney
CLAUDE A. LEWIS, Mayor
ATTEST:
LORRAINE M. WOOD, City Clerk
(SEAL)
Ray Patchett - Melrose Drive Page 1
From: Bob Johnson
To: Ray Patchett
Date: 02/06/2007 9:02:02 AM
Subject: Melrose Drive
*/;L
a-k-o?
All Receive
For the Information of the:
CITY COUNCIL^
Asst. CM W"~CA t^CC
^ity Managef-^^—*
Ray, after our discussion yesterday, I spoke with the traffic engineer for Vista, Art Brown. I also drove the
segment of Melrose Drive in Vista north of the Carlsbad north city limit. Melrose Drive has six traffic
lanes with a raised median in Vista continuing northerly to Sycamore Avenue. Vista designates Melrose
Drive as a prime arterial roadway in their Circulation Element, just as we also designate Melrose Drive as
a prime arterial in our Circulation Element.
Vista traffic engineering staff conducted an Engineering and Traffic Survey for Melrose Drive in August
2005 when the road terminated at the Vista south city limit and had only local traffic using the road. Since
the road has been opened, the road serves regional traffic. They have not updated their survey since the
road was extended into Carlsbad in August 2006. They measured critical speeds on Melrose Drive in
August 2005 when the road terminated at the south city limit of 47 and 49 miles per hour. These two
critical speeds support their posted speed limit of 50 miles per hour.
Mr. Brown indicated that he has no plans to update the engineering and traffic survey now that Melrose
Drive has been extended into Carlsbad. He acknowledges that if a speeding citation is thrown out of court
because of an invalid engineering and traffic survey because of the changed roadway conditions (the road
being opened into Carlsbad), then he will have to update and prepare a new engineering and traffic survey
and the speed limit may need to be raised.
The critical speed in Carlsbad on Melrose Drive north of Palomar Airport road is 54 miles per hour. This
critical speed supports the recommended 55 mile per hour speed limit in Carlsbad. The posted speed
limit on Melrose Drive south of Palomar Airport Road is also 55 miles per hour.
CC:Glenn Pruim; Lisa Hildabrand; Ron Ball
SPEED LIMIT FOR MELROSE DRIVE NORTH OF PALOMAR
AIRPORT ROAD
Honorable Mayor Bud Lewis
City Council Members
As residents of Rancho Carrillo, we experience our neighborhood's traffic situations
on a daily basis. We observe and experience these traffic issues not as technical
engineers, but as drivers, pedestrians and homeowners. We see where visibility is
reduced, where caution is needed, and where congestion affects the flow of traffic.
And we observe the near misses and small accidents that are not reported to the
police department. Tonight we are here representing more than 3000 homeowners,
who live in Rancho Carrillo. We are requesting your action regarding the speed limit
on north Melrose Drive. Based on our observations we present to you that setting
the speed limit at 55, as the City of Carlsbad's Traffic Division is recommending, will
create a condition that could endanger the lives of the motoring public, and may
violate CALTRANS roadway design directives.
Rules and methods of establishing speed limits in Carlsbad
The City of Carlsbad's Traffic Division has educated us on how traffic speeds are
established. We understand that the speed is determined by:
1) Taking a Traffic & Engineering Survey
2) Using the 85% rule for setting speed limits
3) The general assumption that the Drivers, theoretically, will drive within prevailing
speed and conditions on the roadway.
4) History of major accidents in the community in question.
We believe there is a missing element in these calculations that is the roadside
conditions not readily apparent to the driver. These definitely apply to the special
conditions that exist around Melrose Drive at Palomar Airport Road. While rules will
give uniformity to the process, they should be used as guidelines and in light of the
reality of the situation. The lack of fatal accidents in our neighborhood does not mean
that there have not been many close calls. Lack of major accidents should not be
used to justify higher speed limits for a new section of road such as Melrose Drive.
No one wants a major accident to happen that then leads to a change that should
have been apparent all along.
North Melrose Drive's Speed Limit
The following is an illustration of how the residents of Rancho Carrillo repeatedly
have tried to bring their issues to the Traffic and Safety Commission and to the City
of Carlsbad's Traffic Division. In late December of 2006, we addressed the Traffic
and Safety Commission, regarding the speed limit on the extension of North Melrose
from Palomar Airport Road to the City of Vista's southern boundary, a distance of
approximately % mile. The City of Carlsbad's Traffic Division recommended a speed
limit of 55 MPH. We felt that was inappropriate given the merging lane changes
1
before and after the intersection, the slope and curves, the expected very high
volume of traffic and congestion in the intersection, plus the obstructed visibility
northbound, and the fact that the City of Vista's posted speed limit is 50 MPH.
While the Traffic and Safety Commissioners indicated they shared and understood
our concerns and issues, they decided to accept the City of Carlsbad's Traffic
Division recommendation. Their decision was based on Mr. Johnson's repeated
warnings that if the police officers issue citations, the courts will not uphold those
citations, because lowering the speed limit below the Traffic & Engineering Survey's
85 Percentile is creating a speed trap! We don't understand this logic. We present to
you that setting the speed limit at 55 MPH, while the adjoining City's limit is 50 MPH,
will create a Speed Trap in Vista.
Our understanding is that the City of Carlsbad currently has 6 traffic officers for all of
the City's streets and schools. In 2005 the Police Department committed to having an
officer at Carrillo Elementary School once a week. This does not happen regularly.
Unfortunately, there are not enough traffic police in Carlsbad to enforce the traffic
laws and safe driving practices on a regular basis. In reality, how often will the police
be present in the % mile distance of North Melrose using radar to issue tickets?
Motorists are often turning on to Melrose, accelerating from a slow speed, going
down hill, dealing with lane changes, curves, and approaching another signalized
intersection at Lionsgate Avenue, not where police would normally try and set up
radar to catch speeders. And if they did set up radar, how often would these tickets
be challenged? Does the threat of not being able to use radar in this small section of
roadway override the safety of citizens?
We have been told by the City's Police Division that the drivers have to drive 12 miles
above the posted speed limit before the traffic officers ticket them. This means that
by setting the speed limit on North Melrose Drive at 55 MPH you are really setting it
at 66 MPH without giving tickets for speeding. Is this rational? Is it worth risking the
lives of the residents of Carlsbad?
Let us relate to you our concerns point by point.
1. The City's traffic volume projection based upon Linscott Law & Greenspan's
traffic study prepared for the Villages of La Costa indicates peak volumes of
1390 vehicles per hour through the intersection on Melrose in one direction in
2020. That is almost the same volume that El Camino Real and Palomar
Airport Road will have in the same year.
2. Based upon those projections, Melrose northbound at the intersection is being
built to allow 2 left turn lanes, 4 straight ahead lanes (an increase from the 3
lanes south of the intersection), a bike lane and a right turn lane.
3. North of the intersection with Palomar Airport Road, at Lionsgate Avenue,
northbound Melrose again is reduced to 3 lanes requiring the number 4 lane to
merge into the number 3 lane.
4^ Melrose northbound crests at Palomar Airport Road and drops off steeply on
the north side making the roadway, any cars or obstructions on it not visible
to northbound drivers until they are in the intersection. Here are photos from a
vehicle stopped at the light. See how the cars disappear. And, a view halfway
across the intersection. Notice that you cannot see very far ahead and that
the road curves steeply down and to the right.
5. Vehicles stopping for backed-up traffic, slowing to merge, or trying to avoid an
accident or a disabled vehicle, are not visible to northbound vehicles until they
are too close to have time to stop safely.
6. At 55 MPH, CALTRANS states in Table 201.1 of the Highway Design Manual
that a passenger vehicle would need 500 feet to stop in an emergency on a
level roadway. A vehicle will need even more distance to stop on a slope such
as Melrose. Here is a photo from 500 feet north of Palomar Airport Road that
shows you cannot see cars stopped at the light in lanes 4 & 5 or even the
driver of a SUV stopped at the light in lane 3.
7. When a car is stopped at the light on Melrose northbound, they cannot see a
4.25 foot tall object on the roadway 300 feet ahead. A moving car at that point
also cannot see an object 300 feet ahead. At 40 MPH a driver would need
300 feet to stop safely per CALTRANS Table 201.1 of the Highway Design
Manual. Here is a photo from 300 feet north of Palomar Airport Road looking
south that shows you cannot see cars stopped at the light in lanes 3, 4 & 5 at
Palomar Airport Road or even the driver of a SUV turning at the light from lane
2,
We contend that, specifically for northbound motorists on Melrose who have severely
limited visibility past Palomar Airport Road, the speed limit should be lowered before
they get to the intersection. There is an up slope on Melrose just before getting to
Palomar Airport Road that acts to launch a vehicle going 55 MPH, having it bounce
once at about midway across Palomar Airport Road and then again north of the
intersection. This photo shows the launch ramp. Isn't it the City's duty to address
such an issue so motorists do not lose control of their vehicle as they fly through the
intersection? Shouldn't the City's signage give them a warning, because they will not
be able to see any obstruction on the other side of the intersection until they have
crossed the intersection? Just to set a 55 MPH speed limit because of a Traffic &
Engineering Survey 85 Percentile rule seems irresponsible. We, the motoring public,
expect that Cities set speed limits that are appropriate for the conditions that we may
not know will occur ahead of us, not just to meet a written standard for open
highways.
The California Traffic Regulations Section 8-03.3B for Engineering and Traffic
Survey states that a Traffic Survey shall include "roadside conditions not readily
apparent to the driver." It should be obvious that launching a vehicle at an
intersection and obstructed visibility are conditions that are not readily apparent to
the driver approaching that portion of roadway
We believe the speed limit on Melrose Drive northbound should be reduced to 45
MPH starting 450 feet south of the intersection with Palomar Airport Road and
continuing to Lionsgate Avenue, and 45 MPH from Lionsgate Avenue to Palomar
Airport Road southbound. Speed limit signs indicating 45 MPH should be posted at
the 450 foot mark as well as 45 MPH Speed Zone Ahead signs 450 feet before the
speed zone starts.
An Example of the Exception to the rules in the City of Carlsbad
Palomar Airport Road and Melrose Drive have one thing in common: they both have
6 lanes. Palomar Airport Road does not have any homes or schools, Melrose does.
However, the traffic speed on Palomar Airport Road between Paseo Del Norte and
Armada Drive is posted as 45 MPH. This portion of the road is flat with no obstructed
views. One can only assume that the lower speed limit is placed on this portion of
Palomar Airport Road because of the increased congestion. What traffic rules were
used to set that speed limit? Why are the same rules for this situation not used to
justify a lower speed limit on Melrose Drive at Palomar Airport Road or other
congested areas?
Our Recommendation
We ask that the speed limit on Melrose Drive north of Palomar Airport Road in both
directions be set at 45 MPH. We also request that the speed limit on northbound
Melrose Drive be set at 45 MPH starting 450 feet south of the intersection with
Palomar Airport Road with an appropriate speed zone warning sign an additional 450
feet south.
Finally, we came here as citizens of Carlsbad concerned about the safety in and
around our community and for the motoring public.
HIGHWAY DESIGN MANUAL 200-1
January 4,2007
CHAPTER 200
GEOMETRIC DESIGN AND
STRUCTURE STANDARDS
Topic 201 - Sight Distance
Index 201.1 - General
Sight distance is the continuous length of highway
ahead visible to the driver. Four types of sight
distance are considered here: passing, stopping,
decision, and corner. Passing sight distance is used
where use of an opposing lane can provide passing
opportunities (see Index 201.2). Stopping sight
distance is the minimum sight distance to be
provided on multilane highways and on 2-lane
roads when passing sight distance is not
economically obtainable. Stopping sight distance
also is to be provided for all elements of
interchanges and intersections at grade, including
private road connections (see Topic 504, Index
405.1, & Figure 405.7). Decision sight distance is
used at major decision points (see Indexes 201.7
and 504.2). Corner sight distance is used at
intersections (see Index 405.1, Figure 405.7, and
Figure 504.3J).
Table 201.1 shows the standards for stopping
sight distance related to design speed, and these
shall be the minimum values used in design.
Also shown are the values for use in providing
passing sight distance.
Chapter 3 of "A Policy on Geometric Design of
Highways and Streets," AASHTO, contains a
thorough discussion of the derivation of stopping
sight distance.
201.2 Passing Sight Distance
Passing sight distance is the minimum sight
distance required for the driver of one vehicle to
pass another vehicle safely and comfortably.
Passing must be accomplished assuming an
oncoming vehicle comes into view and maintains
the design speed, without reduction, after the
overtaking maneuver is started.
Table 201.1
Sight Distance Standards
Design Speed(1)
(mph)
20
25
30
35
40
45
50
55
60
65
70
75
80
Stopping
(ft)
125
150
200
250
300
360
430
500
580
660
750
840
930
Passing
(ft)
800
950
1,100
1,300
1,500
1,650
1,800
1,950
2,100
2,300
2,500
2,600
2,700
(1) See Topic 101 for selection of design speed.
(2) For sustained downgrades, refer to advisory standard in
Index 201.3
The sight distance available for passing at any
place is the longest distance at which a driver
whose eyes are 3 1A feet above the pavement
surface can see the top of an object 4 % feet high
on the road. See Table 201.1 for the calculated
values that are associated with various design
speeds.
hi general, 2-lane highways should be designed to
provide for passing where possible, especially
those routes with high volumes of trucks or
recreational vehicles. Passing should be done on
tangent horizontal alignments with constant grades
or a slight sag vertical curve. Not only are drivers
reluctant to pass on a long crest vertical curve, but
it is impracticable to design crest vertical curves to
provide for passing sight distance because of high
cost where crest cuts are involved. Passing sight
distance for crest vertical curves is 7 to 17 times
longer than the stopping sight distance.
Ordinarily, passing sight distance is provided at
locations where combinations of alignment and
200-2
January 4,2007
HIGHWAY DESIGN MANUAL
profile do not require the use of crest vertical
curves.
Passing sight distance is considered only on 2-lane
roads. At critical locations, a stretch of 3- or 4-lane
passing section with stopping sight distance is
sometimes more economical than two lanes with
passing sight distance.
Passing on sag vertical curves can be accomplished
both day and night because headlights can be seen
through the entire curve.
See Part 3 of the Manual on Uniform Traffic
Control Devices (MUTCD) for criteria relating to
the placement of barrier striping for no-passing
zones. Note, that the passing sight distances shown
in the MUTCD are based on traffic operational
criteria. Traffic operational criteria are different
from the design characteristics used to develop the
values provided in Table 201.1 and Chapter 3 of
AASHTO, A Policy on Geometric Design of
Highways and Streets. The aforementioned table
and AASHTO reference are also used to design the
vertical profile and horizontal alignment of the
highway. Consult the Headquarters (HQ) Traffic
Liaison when using the MUTCD criteria for traffic
operating-control needs.
Other means for providing passing opportunities,
such as climbing lanes or turnouts, are discussed in
Index 204.5. Chapter 3 of AASHTO, A Policy on
Geometric Design of Highways and Streets,
contains a thorough discussion of the derivation of
passing sight distance.
201.3 Stopping Sight Distance
The minimum stopping sight distance is the
distance required by the driver of a vehicle,
traveling at a given speed, to bring the vehicle to a
stop after an object on the road becomes visible.
Stopping sight distance is measured from the
driver's eyes, which are assumed to be 3 1A feet
above the pavement surface, to an object Vi-foot
high on the road. See Index 1003.1(9) for bicycle
stopping sight distance guidance.
The stopping sight distances in Table 201.1 should
be increased by 20 percent on sustained
downgrades steeper than 3 percent and longer than
one mile.
201.4 Stopping Sight Distance at Grade
Crests
Figure 201.4 shows graphically the relationships
between length of crest vertical curve, design
speed, and algebraic difference hi grades. Any one
factor can be determined when the other two are
known.
201.5 Stopping Sight Distance at Grade
Sags
From the curves in Figure 201.5, the minimum
length of vertical curve which provides headlight
sight distance in grade sags for a given design
speed can be obtained.
If headlight sight distance is not obtainable at grade
sags, lighting may be considered. The Design
Coordinator and the HQ Traffic Liaison shall be
contacted to review proposed grade sag lighting to
determine if such use is appropriate.
201.6 Stopping Sight Distance on
Horizontal Curves
Where an object off the pavement such as a bridge
pier, building, cut slope, or natural growth restricts
sight distance, the minimum radius of curvature is
determined by the stopping sight distance.
Available stopping sight distance on horizontal
curves is obtained from Figure 201.6. It is assumed
that the driver's eye is 3 Vi feet above the center of
the inside lane (inside with respect to curve) and
the object is Vi-foot high. The line of sight is
assumed to intercept the view obstruction at the
midpoint of the sight line and 2 feet above the
center of the inside lane when the road profile is
flat (i.e. no vertical curve). Crest vertical curves
can cause additional reductions in sight distance.
The clear distance (rri) is measured from the center
of the inside lane to the obstruction.
The design objective is to determine the required
clear distance from centerline of inside lane to a
retaining wall, bridge pier, abutment, cut slope, or
other obstruction for a given design speed. Using
radius of curvature and minimum sight distance for
that design speed, Figure 201.6 gives the clear
distance (m) from centerline of inside lane to the
obstruction.
HIGHWAY DESIGN MANUAL 200-3
January 4,2007
When the radius of curvature and the clear distance
to a fixed obstruction are known, Figure 201.6 also
gives the sight distance for these conditions.
See Index 101.1 for technical reductions in design
speed caused by partial or momentary horizontal
sight distance restrictions. See Index 203.2 for
additional comments on glare screens.
Cuts may be widened where vegetation restricting
horizontal sight distance is expected to grow on
finished slopes. Widening is an economic trade-off
that must be evaluated along with other options.
See Index 902.2 for sight distance requirements on
landscape projects.
201.7 Decision Sight Distance
At certain locations, sight distance greater than
stopping sight distance is desirable to allow drivers
time for decisions without making last minute
erratic maneuvers (see Chapter in of AASHTO, A
Policy on Geometric Design of Highways and
Streets, for a thorough discussion of the derivation
of decision sight distance.)
On freeways and expressways the decision sight
distance values in Table 201.7 should be used at
lane drops and at off-ramp noses to interchanges,
branch connections, roadside rests, vista points, and
inspection stations. When determining decision
sight distance on horizontal and vertical curves,
Figures 201.4, 201.5, and 201.6 can be used.
Figure 201.7 is an expanded version of Figure
201.4 and gives the relationship among length of
crest vertical curve design speed, and algebraic
difference hi grades for much longer vertical curves
than Figure 201.4.
Decision sight distance is measured using the
3 l/2-foot eye height and Vi-foot object height. See
Index 504.2 for sight distance at secondary exits on
a collector-distributor road.
Table 201.7
Decision Sight Distance
Design Speed
(mph)
30
35
40
45
50
55
60
65
70
75
80
Decision Sight
Distance
(ft)
450
525
600
675
750
865
990
1,050
1,105
1,180
1,260
Topic 202 - Superelevation
202.1 Basic Criteria
According to the laws of mechanics, when a
vehicle travels on a curve it is forced outward by
centrifugal force.
On a superelevated highway, this force is resisted
by the vehicle weight component parallel to the
superelevated surface and side friction between the
tires and pavement. It is impractical to balance
centrifugal force by superelevation alone, because
for any given curve radius a certain superelevation
rate is exactly correct for only one driving speed.
At all other speeds there will be a side thrust either
outward or inward, relative to the curve center,
which must be offset by side friction.
If the vehicle is not skidding, these forces are in
equilibrium as represented by the following
equation, which is used to design a curve for a
comfortable operation at a particular speed:
Centriugal Factor = e + f =0.067V2
15R
HIGHWAY DESIGN MANUAL 400-7
January 4,2007
404.3 Turning Templates
(1) General. The truck-turn template is a design
aid for locating the wheel paths of large
vehicles as they turn through at-grade
intersections. Consideration should be given to
the overhang of the truck, where the body of
the truck slightly extends (approximately
2 feet) beyond the wheel path. The template is
useful for determining corner radii, for
positioning island noses, and for establishing
clearance to bridge piers, signal poles, and
other hardware at intersections. Templates can
help determine the width of a channeled
separate turning lane. Topic 407 illustrates
scaled turning templates for the various design
vehicles and turning radii.
(2) STAA Truck. The STAA truck-turn templates
should be used in the design of all new
interchanges and intersections on the National
Network and on routes leading from the
National Network to designated service and
terminal routes. On rehabilitation projects they
should be used at interchanges and
intersections proposed as service or terminal
access routes. In some cases, factors such as
cost, right of way, environmental issues, local
agency desires, and the type of community
being served may limit the use of the STAA
templates. In those cases, other appropriate
templates should be used.
The minimum practical turning radius is 50
feet. However, the 60-foot radius develops
less swept width and may have an advantage.
The 60-foot radius should be used in most
situations, but the 50-foot radius is acceptable
in restricted situations.
(3) California Truck. The California truck-turn
template should be used in the design of
highways not on the National Network. The
minimum practical turning radius is 50 feet
(4) Bus. At intersections where truck volumes are
light or where the predominate truck traffic
consists of mostly 3-axle and 4-axle units, the
bus turning template may be used. Its wheel
paths sweep a greater width than 3-axle
delivery trucks and the smaller buses such as
school buses, but a slightly lesser width than a
4-axle truck.
Topic 405 - Intersection Design
Standards
405.1 Sight Distance
(1) Stopping Sight Distance. See Index 201.1 for
minimum stopping sight distance requirements.
(2) Corner Sight Distance.
(a) General~At unsignalized intersections a
substantially clear line of sight should be
maintained between the driver of a vehicle
waiting at the crossroad and the driver of
an approaching vehicle.
Adequate time must be provided for the
waiting vehicle to either cross all lanes of
through traffic, cross the near lanes and
turn left, or turn right, without requiring
through traffic to radically alter their
speed.
The values given in Table 405.1 A provide
7-1/2 seconds for the driver on the
crossroad to complete the necessary
maneuver while the approaching vehicle
travels at the assumed design speed of the
main highway. The 7-1/2 second criterion
is normally applied to all lanes of through
traffic in order to cover all possible
maneuvers by the vehicle at the crossroad.
However, by providing the standard corner
sight distance to the lane nearest to and
farthest from the waiting vehicle, adequate
time should be obtained to make the
necessary movement. On multilane
highways a 7-1/2 second criterion for the
outside lane, in both directions of travel,
normally will provide increased sight
distance to the inside lanes. Consideration
should be given to increasing these values
on downgrades steeper than 3 percent and
longer than 1 mile (see Index 201.3),
where there are high truck volumes on the
crossroad, or where the skew of the
intersection substantially increases the
distance traveled by the crossing vehicle.
400-8
January 4, 2007
HIGHWAY DESIGN MANUAL
In determining coiner sight distance, a set
back distance for the vehicle waiting at the
crossroad must be assumed. Set back for
the driver on the crossroad shall be a
minimum of 10 feet plus the shoulder
width of the major road but not less
than 13 feet. Corner sight distance is to be
measured from a 3.5-foot height at the
location of the driver on the minor road to
a 4.25-foot object height in the center of
the approaching lane of the major road. If
the major road has a median barrier, a
2-foot object height should be used to
determine the median barrier set back.
hi some cases the cost to obtain 7-1/2
seconds of comer sight distances may be
excessive. High costs may be attributable
to right of way acquisition, building
removal, extensive excavation, or
immitigable environmental impacts. In
such cases a lesser value of comer sight
distance, as described under the following
headings, may be used.
(b) Public Road Intersections (Refer to Topic
205V-At unsignalized public road
intersections (see Index 405.7) corner sight
distance values given in Table 405.1 A
should be provided.
At signalized intersections the values for
corner sight distances given in Table
405.1 A should also be applied whenever
possible. Even though traffic flows are
designed to move at separate times,
unanticipated vehicle conflicts can occur
due to violation of signal, right turns on
red, malfunction of the signal, or use of
flashing red/yellow mode.
Where restrictive conditions exist,
similar to those listed in Index
405.1 (2)(a), the minimum value for
corner sight distance at both signalized
and unsignalized intersections shall be
equal to the stopping sight distance as
given in Table 201.1, measured as
previously described.
(c) Private Road Intersections (Refer to Index
205.2) and Rural Driveways (Refer to
Index 205.4)~The minimum corner sight
distance shall be equal to the stopping
sight distance as given in Table 201.1,
measured as previously described.
(d) Urban Driveways (Refer to Index 205.3)-
Corner sight distance requirements as
described above are not applied to urban
driveways.
(3) Decision Sight Distance. At intersections
where the State route turns or crosses another
State route, the decision sight distance values
given in Table 201.7 should be used. In
computing and measuring decision sight
distance, the 3.5-foot eve height and the
0.5-foot object height should be used, the
object being located on the side of the
intersection nearest the approaching driver.
The application of the various sight distance
requirements for the different types of
intersections is summarized in Table 405.IB.
(4) Acceleration Lanes for Turning Moves onto
State Highways. At rural intersections, with
stop control on the local cross road,
acceleration lanes for left and right turns onto
the State facility should be considered. At a
minimum, the following features should be
evaluated for both the major highway and the
cross road:
• divided versus undivided
• number of lanes
• design speed
• gradient
• lane, shoulder and median width
• traffic volume and composition
• turning volumes
• horizontal curve radii
• sight distance
• proximity of adjacent intersections
• types of adjacent intersections
For additional information and guidance, refer
to AASHTO, A Policy on Geometric Design of
Highways and Streets, the Headquarters Traffic
Liaison and the Design Coordinator.
HIGHWAY DESIGN MANUAL 400-9
January 4,2007
Table 405.1 A
Corner Sight Distance
(7-1/2 Second Criteria)
Design Speed
(mph)
25
30
35
40
45
50
55
60
65
70
Corner Sight
Distance (ft)
275
330
385
440
495
550
605
660
715
770
Table 405.1 B
Application of Sight Distance
Requirements
Intersection Sight Distance
Types Stopping Corner Decision
Private Roads X
Public Streets and X
Roads
Signalized X
Intersections
X1"
X
(2)
State Route Inter-
sections & Route
Direction
Changes, with or
without Signals
X
(1) Using stopping sight distance between an eye height of 3.5 ft and an
object height of 4.25 ft. See Index 405.1(2Xa) for setback
requirements.
(2) Apply coiner sight distance requirements at signalized intersections
whenever possible due to unanticipated violations of the signals or
malfunctions of the signals. See Index 405.1(2)(b).
405.2 Left-turn Channelization
(1) General The purpose of a left-turn lane is to
expedite the movement of through traffic,
control the movement of turning traffic,
increase the capacity of the intersection, and
improve safety characteristics.
The District Traffic Branch normally
establishes the need for left-turn lanes. See
"Guidelines for Reconstruction of
Intersections," August 1985, published by the
California Division of Transportation
Operations.
(2) Design Elements.
(a) Lane Width - The lane width for both
single and double left-turn lanes on
State highways shall be 12 feet. Under
certain circumstances (listed below), left-
turn lane widths of 11 feet or as narrow as
10 feet may be used on RRR or other
projects on existing State highways and on
roads or streets under other jurisdictions
when supported by an approved design
exception pursuant to Index 82.2. When
considering lane width reductions adjacent
to curbed medians, refer to Index 303.5 for
guidance on effective roadway width;
which may vary depending on drivers'
lateral positioning and shy distance from
raised curbs.
• On high speed rural highways or
moderate speed suburban highways
where width is restricted, the minimum
width of single or dual left-turn lanes
may be reduced to 11 feet.
• In severely constrained situations on
low to moderate speed urban highways
where large trucks are not expected,
the minimum width of single left-turn
lanes may be reduced to 10 feet. When
double left-turn lanes are warranted
under these same circumstances the
width of each lane shall be no less than
11 feet. This added width is needed to
assure adequate clearance between
turning vehicles.
Melrose Speed LimitMelrose Speed LimitPresented by Presented by Residents of Rancho CarrilloResidents of Rancho Carrillo
Our ConcernsOur Concerns1.1.The CityThe City’’s proposal has not s proposal has not taken into consideration taken into consideration ““roadside conditions not roadside conditions not readily apparent to the driver.readily apparent to the driver.””
Our ConcernsOur Concerns2.2.Community input regarding Community input regarding concerns for safety.concerns for safety.
Our ConcernsOur Concerns3.3.Enforcement of traffic regulationsEnforcement of traffic regulations
Our ConcernsOur Concerns4. The City4. The City’’s traffic volume s traffic volume projection indicates peak projection indicates peak volumes of 1390 vehicles per volumes of 1390 vehicles per hour through the intersection on hour through the intersection on Melrose in one direction in 2020. Melrose in one direction in 2020.
Our ConcernsOur Concerns5.5.Based upon those projections, Based upon those projections, Melrose northbound at the Melrose northbound at the intersection is being built to intersection is being built to allow 2 left turn lanes, 4 allow 2 left turn lanes, 4 straight ahead lanes (an straight ahead lanes (an increase from the 3 lanes increase from the 3 lanes south of the intersection), a south of the intersection), a bike lane and a right turn lane.bike lane and a right turn lane.
Our ConcernsOur Concerns6.6.North of the intersection with North of the intersection with Palomar Airport Road, at Palomar Airport Road, at LionsgateLionsgateAvenue, northbound Avenue, northbound Melrose again is reduced to 3 Melrose again is reduced to 3 lanes requiring the number 4 lanes requiring the number 4 lane to merge into the number lane to merge into the number 3 lane.3 lane.
Our ConcernsOur Concerns7.7.Melrose northbound crests at Melrose northbound crests at Palomar Airport Road and Palomar Airport Road and drops off steeply on the north drops off steeply on the north side making the roadway, any side making the roadway, any cars or obstructions on it cars or obstructions on it NOT NOT VISIBLEVISIBLEto northbound drivers to northbound drivers until they are in the intersection. until they are in the intersection.
Our ConcernsOur Concerns8.8.On Melrose north of Palomar On Melrose north of Palomar Airport Road, Airport Road, vehicles stopping vehicles stopping for backedfor backed--up traffic, slowing to up traffic, slowing to merge, or trying to avoid an merge, or trying to avoid an accident or a disabled vehicle, accident or a disabled vehicle, are not visible to northbound are not visible to northbound vehicles until they are too close vehicles until they are too close to have time to stop safely.to have time to stop safely.
Our ConcernsOur Concerns9.9.At 55 MPH, CALTRANS states in At 55 MPH, CALTRANS states in Table 201.1 of the Highway Table 201.1 of the Highway Design Manual, that a passenger Design Manual, that a passenger vehicle would need 500 feet to vehicle would need 500 feet to stop in an emergency on a level stop in an emergency on a level roadway. roadway. A vehicle will need even more A vehicle will need even more distance to stop on a slope such distance to stop on a slope such as Melrose. as Melrose.
Our ConcernsOur Concerns10.10.When a car is stopped at the light on When a car is stopped at the light on Melrose northbound, they cannot Melrose northbound, they cannot see a 4.25 foot tall object on the see a 4.25 foot tall object on the roadway 300 feet ahead. A moving roadway 300 feet ahead. A moving car approaching the intersection at car approaching the intersection at that point also cannot see an object that point also cannot see an object 300 feet ahead. At 40 MPH a driver 300 feet ahead. At 40 MPH a driver would need 300 feet to stop safely would need 300 feet to stop safely on a level roadway per CALTRANS on a level roadway per CALTRANS Table 201.1 of the Highway Design Table 201.1 of the Highway Design Manual. Manual.
Our ConcernsOur Concerns11.11.There is also an up slope on There is also an up slope on Melrose just before getting to Melrose just before getting to Palomar Airport Road that acts as Palomar Airport Road that acts as a launch for vehicles going 55 a launch for vehicles going 55 MPH. MPH.
Our ConcernsOur Concerns12.12.Section 8Section 8--03.3B of the California 03.3B of the California Traffic Regulations states that an Traffic Regulations states that an Engineering and Traffic Survey Engineering and Traffic Survey shall includeshall include““roadside roadside conditions not readily apparent to conditions not readily apparent to the driverthe driver””..
Our ConcernsOur Concerns13.13.An example of a similar situation An example of a similar situation where speed is reduced due to where speed is reduced due to congestion in the City of Carlsbadcongestion in the City of Carlsbad
We propose that the speed limit on Melrose We propose that the speed limit on Melrose Drive northbound should be reduced to Drive northbound should be reduced to 45 45 MPHMPH450 feet south of the intersection with 450 feet south of the intersection with Palomar Airport Road and continuing to Palomar Airport Road and continuing to LionsgateLionsgateAvenue, and Avenue, and 45 MPH45 MPHfrom from LionsgateLionsgateAvenue to Palomar Airport Road Avenue to Palomar Airport Road southbound.southbound.Speed limit signs indicating 45 MPH should Speed limit signs indicating 45 MPH should be posted at the start of the speed zone as be posted at the start of the speed zone as well as well as 45 MPH Speed Zone Ahead45 MPH Speed Zone Aheadsigns signs 450 feet before the speed zone starts.450 feet before the speed zone starts.