HomeMy WebLinkAbout1987-12-07; Traffic Safety Commission; ; Requesting that a four-way STOP intersection be established of Elm Avenue and Chatham RoadCITY OF CARLSBAD
TRAFFIC SAFETY C0114ISSION
COMMISSION REPORT OF: December 7, 1987 ITEM NO. 6A
LOCATION: Intersection of Elm Avenue and Chatham Road
INITIATED BY: Cheryl Ernst, Principal, Hope Elementary School, 3010 Tamarack•
Avenue, Carlsbad, California 92008
BACKGROUND:
DATA:
Ms. Ernst, in her letter of October 5, 1987, is requesting that a four-way
STOP intersection be established at the Elm Avenue/Chatham Road intersection.
At this time, STOP signs control Chatham Road, however no controls have
been placed on Elm Avenue.
Elm Avenue is designated as a Secondary ·Arterial on the Circulation
Element of the General Plan. Chatham Road is a residential street
intersecting Elm Avenue and provides access to a portion of the Calavera
Hills area.
A recent traffic count was obtained at the Elm/Chatham intersection to
determine if a 4-way STOP is warranted. Approach volumes and the total
entering volume is shown on Exhibit 1. Warrants for STOP sigh installations
contained in the CALTRANS Traffic Manual are also attached. At this
location, the 85th percentile speed on Elm. Avenue is 41 mil es per hour,
therefor the minimum vehicular volume is 70% of the stated volume warrant.
It can be observed from Exhibit 1 that there are only four (4) hours of an
average day when the total vehicular volume entering the intersection is
70% of 500 vehicles per hour (350 vehicles) or more.
In the past 12 months, there have been no reported accidents at the Elm
Avenue/Chatham Road intersection. Pedestrian volumes are very 1 ow except
in the morning and afternoon when children are going to and from school,
when approximately 40 pedestrians cross Elm Avenue at Chatham Road.
TRAFFIC SAFETY COMMISSION
COMMISSION REPORT OF: December 7, 1987
(Continued)
RECOMMENDATION:
ITEM NO. 6A
Based upon the low entering volumes, excellent accident record and
adequate sight distance at this intersection, the Traffic Safety Coor-
dinating Committee does not recommend creating a four-way STOP intersection
by installing STOP signs on Elm Avenue at this time. Staff will continue
to monitor this intersection and as volumes increase or conditions change,
the need for a four-way STOP will be re-evaluated.
NECESSARY CITY COUNCIL ACTION:
No City Council action is required unless STOP signs are recommended. In
that case, adoption of an ordinance by the City Council would be required.
\
.&iA',~lsbad Unified School District ~»;;-
801 Pine Avenue, Carlsbad, Callfontlai 9:1008 7:19-9291
October 5, 1987
Mr. Mike Shirey
Traffic Engineer Technician
City of Carlsbad Engineering Dept.
2075 Las Palmas Drive
Carlsbad, CA 92008
Dear Mr. Shirey:
uExcellence In Education"
As you know, we have had several conversations regarding the safety of the
students to and from Hope Elementary School this year. Many of my parents are
still very concerned about certain intersections and other safety hazards. I
have formed a committee of the concerned parents to study th.e issues and
prioritize them and seek alternatives.
The purpose of this letter is to inform you that the parent representatives
and I would like very much to have an opportunity to speak with the Traffic
Commi~sion regarding the intersection of Chatham and Elm Avenue. I have re-
commended to parents through my newsletters, as you have suggested, that students
walk down to the Tamarack and Elm crossing for the safe route to school; however,
many youngsters and their parents are utilizing the Chatham and Elm intersection
to cross instead. There have been several near misses with youngsters crossing
in that area, and there have been cars which have had problems entering onto
Elm Avenue from Chatham because of the difficulty. Our parents from the Safety
Committee are recommending that a 4-way stop be placed at that intersection to
enable youngsters to cross in a safer fashion. Our committee is also intending
to recommend that an unmarked car be .placed at that intersection to observe the
patterns of behavior. It is my understanding that you left a message in my office
that you had been conducting this type·of observation and we appreciate that very
much. The parents would still, however, like an opportunity to speak with the
Traffic Commission further on this issue.
I appreciate the time and considerations you have given in our new school's
opening and the safety of our students. I look forward to hearing from you re-
garding their opportunity to attend one of the Traffic Commission meetings.
Cheryl Ern
Principal
CE:jc
Hope Elementary School, 434-0671
CHt\TIW-1 lmD/ELM AVEN.JE
)NIERSECTil14 APmW:H \QlHS
OCTOOER 27-28, 1987
CHt\TIW-1 IID rnt\TIW-1 IID ELM AVE ELM AVE TOTAL TIME SLO ELM AVE N/0 ELM AVE WLO CHt\TIW-1 E/0 rnt\TIW-1 ENITRit,i, VOLLME
CXXXJ-0100 4 1 10 4 19
0100-0200 0 0 5 2 7
0200-0300 3 3 4 5 15
0300-0400 1 2 2 1 6
0400-0500 6 2 2 4 14
0500-0600 10 14 4 25 53
0600-0700 49 51 27 47 174
0700-0!ro 52 108 71 97 328
O!ro-0900 50 163 175 139 527
0900-1000 26 47 54 73 200
1000-1100 32 45 82 73 232
1100-1200 17 39 00 45 181
1200-1300 15 59 102 61 237
1300-1400 25 64 127 76 292
1400-1500 27 89 178 91 385
1500-1600 36 72 108 94 310
1600-1700 32 00 169 82 363
1700-1000 39 66 247 98 450
1000-1900 21 53 153 97 324
1900-2000 28 50 132 56 266
2000-2100 19 26 101 45 191
2100-2200 13 21 101 44 179
2200-2300 12 12 38 17 79
2300-2400 1 5 15 10 31
EXHIBIT 1
SPEED SURVEY
DATE: //-/(p. IP7 THIE:/0."0~o// :0011"'
WEATIIER: ?/eAg -2Vh"'y'
LocATioN: £t!..,,,,, 4Pe. e C44r~# R/
OBSERVER/RECORDER: ____ M_J_~-----
II ',{,
CITY.OF
CARLSBAD
% ',{, ti1e ',{, II
TOTAL VEHICLES : _ __;/_O_O~--
CRITICAL SPEED: ~/ IIPII
PACE SPEED: '-3, t.\-to L.\-l.\ MPII
CA ns IN PACE: __ __.q._o"""'-__ 'J,
Traffic Manual
R1
e
Standard 30"
R1-3 -Standard 12" x 8"
R1-4
i;ilWMi
Standard 18" x 8"
SIGNS
POLICY
Stop Signs and Yield Signs
• Stop Signs
4-37
3-1987
The STOP sign (Rt) shall be used where traffic
Is required to stop except at signalized Intersections.
The STOP sign shall be an octagon with white mes-
sage and border on a red background. The standard
size shall be 30 x 30 inches. Where greater emphasis
or visibility Is required, a larger size Is recommended.
On local streets and secondary roads with low ap-
proach speeds and low volume, a 24 x 24 Inch size
maybe used.
At a multiway stop intersection, a supplemental plate
(R1 ·3 or R1 ·4) should be mounted Just below each
STOP sign.,
The numeral on the supplementary plate shall corres-
pond to the number of approach legs, or the legend
ALL-WAY (R1·4) may be used. The plate shall have
white letters on a red background.
A red flashing beacon or beacons may be used In
conjunction with a STOP sign. See Section 9-08
(Flashng Beacons).
Secondary messages shall not be used on STOP sign
laces.
• Warrants for STOP"Signs
Because the STOP sign causes a substantial Incon-
venience to ·motorists, it should be used only where
warranted. A STOP sign may be warranted at an inter-
section where one or more of the following con-
ditions exist:
1. On the less important road at its Intersection with
a main road where application of the, normal right
of way rule Is unduly hazardous as evidenced by
accidents susceptible to correction by STOP
signs,
2. On a county road or city street at Its Intersection
with a state highway.
3. At the Intersection of two main highways. The
highway traffic to be stopped depends on ap-
proach, speeds, volumes, and turning movements.
4. On a street entering a legally established· through
highway or street.
5. On a minor street where the sale approach speed
to the intersection Is less than 10 mlles·per hour.
6. At an unsignallzed Intersection in a signal·
ized area.
7. At other Intersections where a combination of high
speed, restricted view, and accident record indi·
cates a need tor control by the STOP sign.
4-38
3-1987
SIGNS Traffic Manual
POLICY
A STOP sign Is not a "cure-air" and Is not a substitute
for other traffic control devices. Many times the need
for a STOP sign can be eliminated If the sight distance
Is Increased by remo,ting the obstructions.
STOP signs shall not be erected at any entrance to an
intersection when such entrance is controlled by an
official traffic control signal, nor at any railroad grade
crossing which is controlled by automatic signals,
gates, or other train-actuated control devices except
as provided In eve 21355, Stop Signs. The conflicting
commands of two types of control devices are con-
fusing. If traffic Is required to stop when the operation
of the stop-and-go signals Is not warranted, the signals
should be put on flashing operation with the rad flashing
light facing the traffic that must stop.
Where two main highways intersect, the STOP sign or
signs should normally be posted on the minor street to
stop the lesser flow of traffic. Traffic engineering studies,
however, may justify a decision to Install a STOP sign or
signs on the major street, as at a three-way Intersection
where safety considerations may justify stopping the
greater flow of traffic to permit a left.turning movement
STOP signs should not be Installed Indiscriminately at
all unprotected railroad crossings. The allowance of
STOP signs at all such crossings would eventually bread·
contempt for both law enforcement, and obedience to
the sign's command to stop. STOP signs may only be
used at selected ralVhlghway grade crossings after
their need has been determined by a traffic engineering
study. Such study should consider approach speeds,
sight distance restrictions, volumes, accident records,
etc. This appllcatlon· or STOP signs should be an Interim
use period during which plans for lights, gates or other
means or control are being prepared.
Portable or part-time STOP signs shall not be used except
for emergency purposes. Also, STOP signs should not be
used for speed control.
• Multlway STOP signs
The "Multlway Stop" installation may be useful at some
locations. It should ordinarily be used only where
the volume of traffic on the intersecting roads Is approx·
lmately equal. A traffic control signal Is more satisfactory
for an Intersection with a heavy volume of traffic.
Traffic Manual
R1-2
Standard 38"
SIGNS
POLICY
4-39
3-1987
Any of the following conditions may warrant a multi-
way STOP sign Installation:
1. Where traffic signals are warranted and urgently
needed, the multlway stop may be an interim
measure that can be installed quickly to control
traffic while arrangements are being made tor
the signal Installations.
2. An accident problem, as Indicated by five or more
reported accidents within a 12 month period of
a type susceptible to correction by a multiway
stop Installation. Such accidents Include right-
and left-turn collisions as well as right-angle
collisions.
3. Minimum traffic volumes
(a) The total vehicular volume entering the inter-
section from all approaches must average at
least 500 vehicles per hour for any 8 hours of
an average day, and
(b) The combined vehicular and pedestrian
volume from the minor street or highway must
average at least 200 units per hour for the
same 8 hours, with an average delay to minor
street vehicular traffic of at least 30 seconds
per vehicle during the maximum hour, but
(c) When the BS-percentile approach speed of
the major street traffic exceeds 40 miles per
hour, the minimum vehicular volume warrant
Is 70 percent of the above requirements.
e Yield Signs
The YIELD sign (R1·2) assigns right of way to traffic
on certain approaches to an intersection. Vehicles
controlled by a YIELD sign need stop only when nec-
essary to avoid interference with other traffic that
Is given the right of way.
The YIELD sign shall be a downward pointing, equi•
lateral triangle having a red border band and a white
Interior and the word YIELD In red inside the border
band. The standard size shall be 36 x 36 x 36 Inches.
• Warrants for YIELD Signs
The YIELD sign may be warranted:
1. On a minor road at the entrance to an Intersection
where it ls necessary to assign right of way to the
major road, but where a stop Is not necessary
at all times, and where the safe approach speed
on the minor road exceeds 1 O miles per hour.
2. On the entrance ramp to an expressway where an
acceleration lane is not provided.