HomeMy WebLinkAbout; Carlsbad Blvd Las Encinas Creek & Bridge; Carlsbad Blvd Las Encinas Creek & Bridge; 2009-03-10UNSCOTT
LAW &
GREENSPAN
engineers
TRAFFIC IMPACT ANALYSIS
ENCINAS CREEK BRIDGE
Carlsbad, California
March 10, 2009
Prepared for:
EDAW
1420 Kettner Boulevard
Suite 620
San Diego, California 92101
LLG Ref. 3-09-1874
Prepared by:
Narasimha Prasad
Senior Transportation Engineer
&
Radhika Yechangunja
Transportation Engineer II
Underthe Supervision of:
John Keating, P.E.
Principal Linscott, Law &
Greenspan, Engineers
4542 Ruffner Street
Suite 100
Sar Diego, CA92ni
858.300.8800 T
858.300.8810 F
wmw.llgengireers.com
TABLE OF CONTENTS
SECTION PAGE
LO Introduction 1
2.0 Project Description 4
2.1 Proj ect Location 4
2.2 Background 4
2.3 Project Description : 4
3.0 Existing Conditions 5
3.1 Study Area 5
3.2 Exisdng Street Network 6
3.3 Exisdng Traffic Volumes '. 6
4.0 Analysis Approach and Methodology : 9
4.1 Analysis Approach 9
4.2 Analysis Methodology 9
4.2.1 Signalized Intersections ..9
4.2.2 Street Segments 10
5.0 Significance Criteria 11
6.0 Analysis • 12
6.1 Existing Without Southbound Carlsbad Boulevard Closure 12
6.1.1 Peak Hour Intersection Levels of Service 12
6.1.2 Peak Hour Street Segment Levels of Service 12
6.2 Existing With Southbound Carlsbad Boulevard Closure 12
6.2.1 Traffic Volumes 12
6.2.2 Peak Hour Intersection Levels of Service 12
6.2.3 Peak Hour Street Segment Levels of Service 13
7.0 Bicycle, Pedestrian Traffic and Other Issues 17
7.1 Pedestrian Traffic 17
7.2 Bicycle Traffic 17
7.3 Access to Carlsbad State Beach Campground 17
8.0 Significance of Impacts and Recommendations : 21
8.1 S ignificance of Impacts 21
8.1.1 Direct Impacts 21
8.2 Recommendations 21
LINSCOTT, LAW & GREENSPAN, engineers . LLG Ref. 3-09-1874
i Encinas Creek Bridge
APPENDICES
APPENDIX
A. Intersection and Segment Manual Count Sheets
B. ICU Methodology Explanation & City of Carlsbad Roadway Classification Table
C. Intersection Analysis Worksheets - Existing Conditions
D. Intersection Analysis Worksheets - Existing Conditions with southbound Carlsbad Boulevard
closure
E. Conceptual Sketch of Recommended Striping at the Palomar Airport Road / Avenida Encinas
Intersection
LIST OF FIGURES
SECTION—FIGURE # FOLLOWING PAGE
Figure 1-1 Vicinity Map 2
Figure 1-2 Project Area Map 3
Figure 3-1 Existing Conditions Diagram .' 7
Figure 3-2 Existing Traffic Volumes 8
Figure 6-1 Rerouting of Peak Hour and Daily Traffic Volumes with Southbound Carlsbad
Boulevard Closure 15
Figure 6-2 Existing Traffic Volumes With Southbound Carlsbad Boulevard Closure 16
Figure 7-1 Existing Pedestrian Volumes 18
Figure 7-2 Existing Bicycle Volumes 19
Figure 7-3 Existing Bicycle Volumes With Southbound Carlsbad Boulevard Closure 20
Figure 8-1 Recommended Mitigation Measures 24
Figure 8-2 . Conceptual Striping Plan - Palomar Airport Road / Avenida Encinas Intersection... 25
LIST OF TABLES
SECTION—TABLE # PAGE
Table 4-1 Level of Service Ranges For Signalized Intersections 9
Table 5-1 City ofCarlsbad Traffic Impact Significant Thresholds ; 11
Table 6-1 Intersection Operations Without and With Southbound Carlsbad Boulevard Closure .... 13
Table 6-2 Segment Operations Without and With Southbound Carlsbad Boulevard Closure 14
LiNSCorr, LAW & GREENSPAN, engineers LLG Ref. 3-09-1874
Encinas Creek Bridge
TRAFFICIMPACT ANALYSIS
ENCINAS CREEK BRIDGE
Carlsbad, California
March 10,2009
1.0 INTRODUCTION
This traffic study has been prepared to determine and evaluate the potential traffic impacts to the
local roadway system due to the proposed replacement of an existing Encinas Creek Bridge on
southbound Carlsbad Boulevard in the City of Carlsbad. The project site is located on southbound
Carlsbad Boulevard between Solamar Drive/Carlsbad Boulevard and Island Way/Carlsbad
Boulevard intersections.
Figure 1-1 shows the project vicinity and Figure 1-2 depicts the project area in detail.
The proposed replacement of the bridge is expected to take up to four months, during which time the
southbound Carlsbad Boulevard will be closed to through traffic, between Solamar Drive and Island
Way. This traffic study evaluates the operations of intersections and segments in the project vicinity
that will be potentially impacted due to the detour and the rerouting of traffic.
Included in this traffic.analysis are:
Project Description;
Existing Conditions Discussion;
Traffic Analysis Approach & Methodology;
Significance Criteria;
Analysis (Without and With southbound Carlsbad Boulevard closure);
Other Issues;
Significance of Impacts and Recommendations.
UNSCOTT, LAW & GREENSPAN, engineers LLG Ref 3-09-1874
Encinas Creek Bridge
RIVERSIDE COUNTY
SAN OIEGO COUNTY
WARNER
SPRINGS
Source: LLG Engin«era, 2009
N:\1B74\ngures\aG1874 Rgure 1-1 MILES
LINSCOTT
LAW &
GREENSPAN
Figure 1-1
Vicinity Map
engineers
ENCINAS CREEK BRIDGE
I.A.L
b''A('L
NOT TO SCALE
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•\\v
'4 ^ II, , ->
It )^',/.t
i ^. u.
'iji lie .[I
y 1
ENCINAS CREEK BRIDGE U 1,1
f» ^s" \ , , '
t:''\ " V
. Source: Thome* Guide, 2009
N;\1874\FlgureALLG1874 Figure 1-2
LINSCOTT
LAW &
GREENSPAN
engineers
Figure 1-2
Project Area IVlap
ENCINAS CREEK BRIDGE
2.0 PROJECT DESCRIPTION
2.1 Project Location
The proposed Encinas Creek Bridge project is located on southbound Carlsbad Boulevard between
Solamar Drive and Island Way in the City of Carlsbad.
2.2 Background
The City of Carlsbad proposes to replace the existing Encinas Creek Bridge located along
southbound Carlsbad Boulevard approximately 0.6 miles south of Palomar Airport Road and one
mile north of Poinsettia Lane. The City has identified the need to remove and replace the bridge due
to severe deterioration and recommendations by Caltrans. The project is located at Encinas Creek
along the southern edge of the historic Agua Hedionda Spanish land grant. Southbound Carlsbad
Boulevard is bound on the west by the State Beach and Pacific Ocean; Encinas Creek and the
northbound lanes of Carlsbad Boulevard on the east. The bridge is located just north of the Carlsbad
State Beach Campgrounds.
2.3 Project Description
The City proposes to install a prefabricated arch concrete bridge structure in place of the existing
concrete bridge. The proposed new structure would have a deck width of 45 feet-2 inches, thereby
reducing the overall width of the bridge by 24 feet. This proposed reduction in width, as compared
to the existing structure, is due to the fact that the bridge is currently oversized. Maintaining the
existing bridge deck width is not necessary to provide adequate travel lanes for forecasted traffic
volumes.. In addition, to minimize the construction impacts on the west side, the wing walls would
be placed parallel to the roadway. The current centerline of the roadway would be maintained and
the new bridge footprint would fit completely within the boundaries of the existing structure. The
new bridge would be approximately 2 feet taller than the existing bridge.
The construction of the bridge is expected to take up to four months and would be completed prior to
the Memorial Day holiday. A Detour Plan would be implemented and would detour all southbound
traffic on Carlsbad Boulevard at Palomar Airport Road to Avenida Encinas,-Poinsettia Lane, and
then back to Carlsbad Boulevard. South of Palomar Airport Road, access would be limited to local
residents requiring residential access off of Solamar Drive, to Hilton Garden Inn staff and guests and
to the contractor. The North Ponto day parking lot just south ofthe bridge would be closed to the
public for the duration of construcdon, but would reopen prior to the Memorial Day holiday and
summer season. Changeable message signs would be used to alert traffic of the detour at all major
decision points.
Carlsbad Boulevard is a divided roadway with a wide median between Palomar Airport Road and
Island Way. Northbound traffic operates independently of southbound traffic in this stretch and it
will not be affected by the southbound bridge replacement project.
LiNSCon, LAW & GREENSPAN, engineers LLG Ref 3-09-1874
4 Encinas Creek Bridge
3.0 EXISTING CONDITIONS
Effective evaluation of the traffic impacts associated with the proposed development requires an
understanding ofthe exisdng transportadon system in the project study area. Existing transportation
conditions in the study area include roadway geometry, traffic control, and peak period/daily traffic
flow. The principal roadways in the project study area are described briefly below. The description
includes the physical characteristics, adjacent land uses, and intersection traffic control.
According to the City ofCarlsbad General Plan, Prime Arterials should be 106 feet wide in 126
feet of Right-of-Way (R/W), providing six travel lanes with no curbside parking and left-turn lanes
at major intersections. Major Arterials should be 82 feet wide in 102 feet of R/W, providing four
travel lanes, bike lanes, and left-turn lanes at major intersections. Secondary Arterials should be 64
feet wide in 84 feet of R/W providing two to four travel lanes, bike lanes, and left-turn lanes at major
intersections. Collectors should be 40 feet wide in 60 feet of R/W, providing two or four travel lanes
with curbside parking and left-turn lanes at major intersections. Local Streets should be 34 feet wide
in 60 feet of R/W, providing two travel lanes with curbside parking and no centerline stripe. The
following provides a description of the street system in the project area. Figure 3-1 illustrates the
existing condidons, including the lane geometry for the key intersections in the study area.
3.1 Study Area
Based on the proposed detour plan for traffic on southbound Carlsbad Boulevard, the following
intersections and segments are analyzed in this study.
Intersections
1. Palomar Airport Road / Avenida Encinas
2. Poinsettia Lane / Carlsbad Boulevard
3. Poinsettia Lane / Avenida Encinas
Segments
Palomar Airport Road from Carlsbad Boulevard to Avenida Encinas
Poinsettia Lane from Carlsbad Boulevard to Avenida Encinas
Carlsbad Boulevard from Palomar Airport Road to Poinsettia Lane
Avenida Encinas from Palomar Airport Road to Poinsettia Lane
LINSCOTT, LAW & GREENSPAN, eng/neers ' LLG Ref 3-09-1874
5 Encinas Creek Bridge
3.2 Existing Street Network |
Palomar Airport Road is classified as a Prime Arterial in the City of Carlsbad Circulation Element.
Palomar Airport Road is a two-lane undivided roadway within the study area. The posted speed limit
is 35 mph. There are no bike lanes west of 1-51
Poinsettia Lane is classified as a Major Arterial in the City of Carlsbad Circulation Element.
Poinsettia Lane is a 4-lane divided roadway. No speed limit is posted the vicinity of the project site.
Curbside parking is prohibited and bike lanes are provided.
Carlsbad Boulevard is classified as a Major! Arterial in the City of Carlsbad Circulation Element.
Carlsbad Boulevard is a north-south roadway within the study area. Carlsbad Boulevard is a four-
divided roadway with a median. Carlsbad Boulevard provides bike lanes, intermittent parking and
sidewalks along the roadway. The posted speed limit is 50 mph.
Avenida Encinas is classified as a Secondary Arterial in the City of Carlsbad Circulation Element.
Currently, it is a two-lane undivided roadway with intermittent left turn lane pockets. The posted
speed limit is 40 mph just south of Palomar Airport Road, and reduces to 35 mph near Poinsettia
Lane. Bike lanes are provided only south of the Coaster Station.
Figure 3-1 depicts the existing conditions in the study area.
3.3 Existing Traffic Volumes
The AM (7:00-9:00) and PM (4:00-6:00) peak hour intersection counts were obtained from the City
of Carlsbad's Traffic Monitoring Program that were commissioned in August 2008. The Average
Daily Traffic (ADT) volumes and the AM and PM peak hour bicycle/pedestrian counts were
conducted by LLG during the non-holiday period in February 2009.
Figure 3-2 depicts the existing peak hour turning movement volumes at the key intersections, and
the daily volumes on the street segments. Appendix A contains intersection and segment count
sheets.
LINSCOTT, LAW & GREENSPAN, engineers LLG Ref 3-09-1874
Encinas Creek Bridge
LEGEND
Traffic Signal
BL — Bike Lone
NP - No Parking
TWLTL - Two-Way Left-Turn Lane
XX — Number of lanes, divided (D)
or undivided (U)
7
Poinsettia Ln/
Carlsbad Blvd
PALOMAR AIRPORT RD
Poinsettia Ln/
Avenida Encinas
O Palomar Airport Rd/
Avenida Encinas
REV. 3/10/2009
N:\187*\ngurB«\U.G1fl74 Rgur. 3-1 NOT TO SCALE
LINSCOTT
LAW &
GREENSPAN
engineers
Figure 3-1
Existing Conditions Diagram
ENCINAS CREEK BRIDGE
NOTES:
— ADT (Average Daily Traffic)
shown midblock
— AM/PM peak hour volumes are
shown at the intersections
in
^ in ^
287/293
»-157/719
^252/251
41/33>
270/271-»
49/30>
O) tn 00 oiin Wrp CO \ CM •<!• cn ra
Poinsettia Ln/ Carlsbad Blvd
Q Palomar Airport Rd/
Avenida Encinas
REV. 3/9/2009
N;\187*\n9ur«s\li.GI874 Rgure 3-2 NOT TO SCALE
LINSCOTT
LAW &
GREENSPAN
engineers
Figure 3-2
Existing Traffic Volumes
AM/PM Peak Hours & ADTs
ENCINAS CREEK BRIDGE
4.0 ANALYSIS APPROACH AND METHODOLOGY
4.1 Analysis Approach
This traffic analysis assesses the key intersections and street segments in the project area. The study
area intersections and segments are analyzed in the following scenarios, based on direction from the
City staff, to determine potential impacts to the road network:
• Existing traffic with Current traffic circuladon
• Existing traffic with southbound Carlsbad Boulevard closure south of Solamar Drive
4.2 Analysis Methodology
Level of service (LOS) is the term used to denote the different operating conditions that occur on a
given roadway segment under various traffic volume loads. It is a qualitative measure used to
describe a quantitative analysis taking into account factors such as roadway geometries, signal
phasing, speed, travel delay, freedom to maneuver, and safety. Level of service provides an index to
the operational qualities of a roadway segment or an intersection. Level of service designations
range from A to F, with LOS A representing the best operating conditions and LOS F representing
the worst operating condidons. Level of service designation is reported differently for signalized
intersections and roadway segments, as described below.
4.2.1 Signalized Intersections
The signalized intersections were analyzed using the Intersection Capacity Utilization (ICU) method.
The ICU procedure is based on an article in the Institute of Transportation Engineers Journal, August
1978 and assumes the traffic flow characteristics of signalized intersections. It computes the Level of
Service (LOS) for the total intersection based upon a summation of volume to capacity (V/C) ratios
for the key conflicting movements. The ICU numerical value represents the percent of signal green
time, and thus, the capacity required to serve the traffic demand. The LOS for signalized
intersections varies from A (free flow, little delay) to F ("heavy congestion" conditions).
TABLE 4-1
LEVEL OF SERVICE RANGES FOR SIGNALIZED INTERSECTIONS
Average Control Delay Per Vehicle
(SecondsA' ehicle) Level of Service
0.0 < 0.60 A
0.61 to 0.70 B
071 to 0.80 C
0.81 to 0.90 D
0.91 to 1.00 E
> 1.00 F
LINSCOTT, LAW & GREENSPAN, engineers LLG Ref 3-09-1874
Encinas Creek Bridge
4.2.2 Street Segments
The key street segments in the project area were analyzed on a peak hour basis. The greatest amount
of peak hour turning volumes at an upstream or downstream intersection comprises the volumes
utilized in the analysis. A volume to capacity ratio (V/C) is calculated for each direction of the street
segment during the peak hour. The City of Carlsbad assumes a one-direction capacity of 1,800
vehicles per hour per lane for through lanes. A Level of Service (LOS) is determined by using V/C
thresholds.
LOS is the term used to denote the different operating conditions which occur on a given roadway
segment under various traffic volume loads. It is a qualitative measure used to describe a quantitative
analysis taking into account factors such as roadway geometries, signal phasing, speed, travel delay,
freedom to maneuver, and safety. Level of Service provides an index to the operational qualities of a
roadway segment or an intersection. Level of Service designations range from A to F, with LOS A
representing the best operating conditions and LOS F representing the worst operating conditions.
Level of Service designation is reported differently for signalized and unsignalized intersections, as
well as for roadway segments.
Appendix B contains the ICU Methodology Explanation and the City of Carlsbad Roadway
Classification Table.
LINSCOTT, LAW & GREENSPAN, engineers LLG Ref 3-09-1874
10 Encinas Creek Bridge
5.0 SIGNIFICANCE CRITERIA
As outlined in the City of Carlsbad's Growth Management Plan, a traffic impact is considered to be
significant if the addition of project traffic causes the intersection or street segment LOS to decrease
to worse than LOS D during the peak hour.
For intersections or street segments which are currently operating worse than LOS D, a project
impact will be considered significant if the project causes the ICU value at an intersection to increase
by more than 0.02 or the volume-to-capacity ratio at a segment to increase by more than 0.02.
TABLE 5-1
CITY OF CARLSBAD
TRAFFIC IMPACT SIGNIFICANT THRESHOLDS
LOS"
Without Project
Allowable Increase Due to Project Impacts LOS"
Without Project Roadway Segments
(V/C)''
Intersections
(ICU)*^
A, B, C, D A project's impact is deemed significant'if the LOS is degraded to LOS E or F
E,F 0.02 0.02
Footnotes:
a. LOS
b. v/c
c. ICU
Level of Service
Volume to Capacity Ratio
Intersection Capacity Utilization
LiNscon, LAW & GREENSPAN, engineers 11 LLG Ref 3-09-1874
Encinas Creek Bridge
6.0 ANALYSIS
6.1 Existing Without Southbound Carlsbad Boulevard Closure
The existing peak hour intersections and segment volumes were collected and analyzed with the
existing intersection geometry and street network.
6.1.1 Peak Hour Intersection Levels of Service
Table 6-1 summarizes the existing peak hour intersection operations. As seen in Table 6-1, all
intersections are calculated to operate at an acceptable LOS D or better except the Palomar Airport
Road/Avenida Encinas intersection which is calculated to operate at LOS E during the PM peak
hour.
Appendix C contains the existing peak hour intersection operation worksheets.
6.1.2 Peak Hour Street Segment Levels of Service
Table 6-2 summarizes the segment operations. As seen in Table 6-2, all the segments are calculated
to operate at LOS A under existing conditions.
6.2 Existing With Southbound Carlsbad Boulevard Closure
Intersection and segment analyses were conducted with re-routing ofthe existing southbound traffic
due to the closure during the Encinas bridge replacement.
6.2.1 Traffic Volumes
The existing traffic volumes on southbound Carlsbad Boulevard to and from Solamar Drive, Island
Way and Breakwater Road were reassigned since access to and from these roadway facilities will be
changed with the closure of southbound Carlsbad Boulevard between Solamar Drive and Island
Way. Access to and from Solamar Drive, Island Way and Breakwater Road will still be possible.
Southbound access to Solamar Drive will remain unchanged. Southbound egress from Solamar
Drive will be redirected to Avenida Encinas. Southbound access to Island Way and Breakwater
Road will be redirected to Avenida Encinas. Southbound egress from Island Way and Breakwater
Road will remain unchanged.
Figure 6-1 shows the rerouting of peak hour and daily segment volumes due to the closure, while
Figure 6-2 depicts the existing peak hour and daily segment volumes due to the closure.
6.2.2 Peak Hour Intersection Levels of Service
Table 6-1 summarizes the existing peak hour intersection operations with southbound Carlsbad
Boulevard closed. As seen in Table 6-1, all intersecdons are calculated to continue to operate at an
acceptable LOS D or better, except the Palomar Airport Road/Avenida Encinas intersection which
degrades to LOS F during the PM peak hour.
If the following mitigation is implemented during the bridge replacement, this intersection is
calculated to operate at LOS D. ' '• >
LiNSCon, LAW & GREENSPAN, engineers LLG Ref 3-09-1874
12 Encinas Creek Bridge
• Provide dual vvestbound left-turn lanes
• Provide northbound right-turn overlap phasing
• Prohibit westbound to eastbound U-tums on Palomar Airport Road
Appendix D contains the existing with southbound Carlsbad Boulevard closure peak hour
intersection operation worksheets.
6.2.3 Peak Hour Street Segment Levels of Service
Table 6-2 summarizes the segment operations with the southbound Carlsbad Boulevard closure. As
seen in Table 6-2, with the closure of Carlsbad Boulevard all the segments are calculated to operate
at LOS A.
TABLE 6-1
INTERSECTION OPERATIONS
WITHOUT AND WITH SOUTHBOUND CARLSBAD BOULEVARD CLOSURE
Intersection Control Peak Without Closure With Closure
Intersection Type Hour ICU" LOS ICU" LOS'^
1. Palomar Airport Rd / Avenida Encinas Signal AM 0 Wll B 0.811 D
PM «.')47 E 1.135 I-
With Mitigation" 0.849 D
2. Carlsbad Blvd / Poinsettia Ln Signal AM 0.304 A 0.377 A
PM 0.400 A 0.500 A
3. Poinsettia Ln / Avenida Encinas Signal AM 0.509 A 0.509 A
PM 0.707 C 0.707 C
Footnotes:
a. Intersection Capacity Utilization.
b. Level of Service.
c. LOS and delay with recommended mitigation. Assumed mitigation measures include a second
westbound left-turn lane and northbound right-tum overlap phasing.
LPS
A
B
C
D
E
F
V/C
<0.6
0.61-0.70
0.71-0.80
0.81-0.90
0.91-1.0
>1.0
LiNSCon, LAWS GREENSPAN, engineers
13
LLG Ref 3-09-1874
Encinas Creek Bridge
TABLE 6-2
SEGMENT OPERATIONS
WITHOUT AND WITH SOUTHBOUND CARLSBAD BOULEVARD CLOSURE
Street Segment Dir Peak
Hour
Existing
Capacity"
Without Closure With Closure Street Segment Dir Peak
Hour
Existing
Capacity" Volume V/C'' LOS" Volume V/c'' LOS"
Palomar Airport Road
Carlsbad Boulevard to EB AM 1,800 360 0.20 A 589 0.33 A
Avenida Encinas PM 1,800 334 0.19 A 652 0.36 A
WB AM 1,800 192 0.11 A 63 0.04 A
PM 1,800 895 0.50 A 653 0.36 A
Poinsettia Lane"
Carlsbad Boulevard to EB AM 3,600 153 0.04 A 153 0.04 A
Avenida Encinas PM 3,600 273 0.08 A 273 0.08 A
WB AM 3,600 320 0.09 A 676 0.19 A
PM 3,600 362 0.10 A 919 0.26 A
Carlsbad Boulevard
Palomar Airport Rd to NB AM 3,600 331 0.09 A 355 0.10 A
Poinsettia Ln PM 3,600 640 0.18 •A 709 0.20 A
SB AM 3,600 418 0.12 A 62 0.02 A
PM 3,600 591 0.16 A 34 0.01 A
Avenida Encinas
Palomar Airport Rd to NB AM 1,800 232 0.13 A 232 0.13 A
Poinsettia Ln PM 1,800 532 0.30 A 532 0.30 A
SB AM 1,800 357 0.20 A 627 0.35 A
PM 1,800 432 0.24 A 855 ' 0.48, A
Footnotes:
a.
b.
Capacity based on 1800 vehicles per lane per hour.
Volume to Capacity ratio
Level of Service
LOS
A
B
C
D
E
F
V/C
<0,6
0,61-0.70
0.71.0.80
0.81-0.90
0.91-1.0
>1,0
LINSCOTT, LAW & GREENSPAN, engineers
14 LLG Ref 3-09-1874
Encinas Creek Bridge
NOTES:
— ADT (Average Daily Traffic)
shown midblock
— AM/PM peak hour volumes are
shown at the intersections
CO CO
(+)68/94-»
(+)16l/224>
-.-(-)124/234
^(+)104/18l
PALOMAR AIRPORT RD
Poinsettia Ln/ Carlsbad Blvd
Poinsettia Ln/
Avenida Encinas
. - Closed, portion
of Southbound
Carisbad Boulevard
Palomar Airport Rd/ Avenida Encinas
PACIFIC
OCEAN
REV. 3/'0/2009
N:\l874\Figuros\LLCta74 Hgure 6-' NOT TO SCALE
LINSCOTT
LAW &
GREENSPAN
engineers
Figure 6-
Re-routing of Peak Hour
& Daily Traffic Volumes
AM/PM Peak Hours & ADTs
ENCINAS CREEK BRIDGE
NOTES:
— ADT (Average Daily Traffic)
shown midblock
- AM/PM peak hour volumes are
shown at the intersections
to in CM o>.—
r~- (D ^
V287/293
»-33/485
^356/432
41/33>
338/365-» in 03
210/254> r> o) in 210/254>
CO
Poinsettia Ln/ Carisbad Bivd
... Closed, portion
of Southbound
CarJsbad BouJevard
0 Palomar Airport Rd/ Avenida Encinas
PACIFIC
OCEAN
REV. 3/10/2009
N;\1874\ngure«\LLG1874 Hgure 6-2 NOT TO SCALE
engineers
Figure 6-2
Existing Traffic Volumes
With SB Carlsbad Blvd Closure
AM/PM Peak Hours & ADTs
ENCINAS CREEK BRIDGE
7.0 BICYCLE, PEDESTRIAN TRAFFIC AND OTHER ISSUES
7.1 Pedestrian Traffic
Existing pedestrian volume counts were conducted at Carlsbad Boulevard/Poinsettia Lane and
Poinsettia Lane/Avenida Encinas intersections on Wednesday, February 9, 2009.. Figure 7-1 depicts
the existing pedestrian traffic.
As seen in Figure 7-1, the pedestrian traffic is generally less than 15 pedestrians per hour at each
crossing except across the south leg of the Carlsbad Boulevard/Poinsettia Lane intersection, where
the pedestrian traffic is 21 during the AM peak hour and 28 during the PM peak hour. Thus, the
highest pedestrian traffic is 1 pedestrian every 1.3 signal cycles. Therefore, pedestrian traffic is
unlikely to be impacted by the traffic detour during the bridge replacement.
7.2 Bicycle Traffic
The existing bicycle counts were conducted at Carlsbad Boulevard/Poinsettia Lane and Poinsettia
Lane/Avenida Encinas intersections on Wednesday, February 9, 2009. Figure 7-2 depicts the
existing bicycle traffic, while Figure 7-3 depicts the rerouted bicycle traffic.
When the southbound Carlsbad Boulevard is closed, the southbound bicycle traffic will have to be
rerouted to Avenida Encinas to Poinsettia Lane to southbound Carlsbad Boulevard. As seen in
Figure 7-2, the highest northbound bicycle traffic is 24 in the PM peak hour or approximately 1
bicycle every traffic signal cycle at the Carlsbad Boulevard/Poinsettia Lane intersection. Therefore,
bicycle traffic is unlikely to be impacted by the traffic detour during the bridge replacement.
Even though bicycle traffic during the weekday peak hours is relatively low, it is known to be much
higher during the weekends. The issue with this is not intersection operations but bicycle rider
safety. Southbound bike traffic will be rerouted from Carlsbad Boulevard to Palomar Airport Road
where the bridge width is narrow and there are no bike lanes. Bikes would then be directed to
southbound Avenida Encinas where again, there are no bike lanes, on the northern two-thirds of this
road and some sections are relatively narrow with no paved shoulder. Bikes will have to share the
southbound travel lanes with vehicles.
7.3 Access to Carlsbad State Beach Campground
Currently, the entrance to the Carlsbad State Beach Campground is a right-in access only. Therefore,
the rerouted traffic from southbound Carlsbad Boulevard will be directed to Poinsettia Lane via
Avenida Encinas. This traffic plus the existing traffic on Poinsettia Lane and will have to go north
on Carlsbad Boulevard, make a u-turn at Breakwater Road and return to the campground.
LiNSCon, LAW & GREENSPAN, engineers ' LLG Ref 3-09-1874
17 Encinas Creek Bridge
LEGEND
XX%^ — Pedestrian Volumes No Pedestrion
Volumes
No Pedestrian
Volumes
Poinsettia Ln/
Carlsbad Blvd
PALOMAR AIRPORT RD
Poinsettia Ln/
Avenida Encinas
0 Palomar Airport Rd/
Avenida Encinas
PACIFIC
OCEAN
REV. 3/9/Z009
N:\IB74\ngur8s\U-G1874 Rgura 7-1 NOT TO SCALE
LINSCOTT
LAW &
GREENSPAN
eflg in eers
Figure 7-1
Existing Pedestrian Volumes
AM/PM Peak Hours & ADTs
ENCINAS CREEK BRIDGE
NOTES:
- AM/PM peak hour volumes are
shown at the intersections No
Bicycle
Volumes
No
Bicycle
Volumes
Poinsettia Ln/ Carlsbad Blvd
0 Palomar Airport Rd/ Avenida Encinas
REV. 3/9/2009
N;\187*\Rgore»\LlG'874 Rgur. 7-2 NOT TO SCALE
LINSCOTT
LAW &
GREENSPAN
engineers
Figure 7-2
Existing Bicycle Volumes
AM/PM Peak Hours & ADTs
ENCINAS CREEK BRIDGE
hour volumes are
intersections
Poinsettia Ln/
Carlsbad Blvd
O Palomar Airport Rd/
Avenida Encinas
REV. 3/10/2009 N;\1874\Rgor««\U.G1fl74 Rgure 7-3 •NOT TO SCALE
LINSCOTT
LAW &
GREENSPAN
engineers
Figure 7-3
Existing Bicycle Volumes
With SB Carlsbad Blvd Closure
AM/PM Peak Hours & ADTs
ENCINAS CREEK BRIDGE
8.0 SIGNIFICANCE OF IMPACTS AND RECOMMENDATIONS
8.1 Significance of Impacts
The intersection and segment analyses indicate the following temporary direct impacts due to the
closure of southbound Carlsbad Boulevard:
8.1.1 Direct Impacts ,
a. Palomar Airport Road/Avenida Encinas intersection.
The following should be noted:
• The closure of southbound Carlsbad Boulevard is expected to result in increased traffic
volumes on Palomar Airport Road, on Avenida Encinas between Palomar Airport Road &
Poinsettia Lane, and on Poinsettia Lane between Carlsbad Boulevard & Avenida Encinas,
but the forecast volumes remain within the capacity of these roadways.
The closure of southbound Carlsbad Boulevard is also expected to result in increased traffic
volumes at the Palomar Airport Road/Avenida Encinas, Carlsbad Boulevard/Poinsettia, and
Poinsettia Lane/Avenida Encinas intersections.
8.2 Recommendations
1. Palomar Airport Road / Avenida Encinas intersection
• Provide dual westbound left-turn lanes
• Provide northbound right-turn overlap phasing
• Prohibit westbound to eastbound U-turns on Palomar Airport Road
• Modify signal timing as appropriate due to modified lane designations.
See Figure 8-1 for a graphical representation of the recommended mitigation measures.
Appendix E includes a sketch of the conceptual striping recommended for the Palomar
Airport Road / Avenida Encinas intersection.
If it is not possible to provide the dual westbound left-turn lanes one of the following should
be provided:
a. Provide longer green interval for the westbound left-tum movement with the
existing single left-turn lane and reduce the green time for the eastbound through
movement, or,
b. Convert northbound lanes on Carlsbad Boulevard temporarily to two-way traffic,
with a K-rail separating the two directions of travel, and,
c. If there is sufficient shoulder on Carlsbad Boulevard, provide a bike lane on in the
southbound direction. If not, provide a signed detour for southbound bike traffic
east to Avenida Encinas to Poinsettia Lane, and back to Carlsbad Boulevard.
However, bikes would still be allowed on southbound Carlsbad Boulevard
>
LiNSCon, LAW & GREENSPAN, eng/neers LLG Ref 3-09-1874
21 Encinas Creek Bridge
2. Bicycle Traffic
• When the southbound Carlsbad Boulevard is closed, the southbound bicycle traffic
will have to be rerouted to Poinsettia Lane via Avenida Encinas to southbound
Carlsbad Boulevard. As discussed earlier, the highest northbound bicycle traffic is
24 in the AM peak hour, at the Carlsbad Boulevard/Poinsettia Lane intersection.
Therefore, bicycle traffic is unlikely to be impacted by the traffic detour during the
bridge replacement.
• To enhance the awareness of bicycles to motorists, "Share the Road' signs (Wl 1 and
W16) should be posted on Palomar Airport Road and Avenida Encinas (see Figure
8-1).
3. Access to Carlsbad State Beach Campground
• Currently, the entrance to the campground is a right-in access only. Therefore, the
rerouted traffic from southbound Carlsbad Boulevard will be directed Poinsettia
Lane via Avenida Encinas. This traffic plus the existing traffic on Poinsettia Lane
and will have to go north on Carlsbad Boulevard, make a u-turn at Breakwater Road
and return to the campground.
LINSCOTT, LAW & GREENSPAN, engineers LLG Ref 3-09-1874
22 Encinas Creek Bridge
LEGEND
_Q_ -R3-4
}f - Second Left—turn lane
RTOL - Right-Turn-Gverlap ,
NOTE:
- Recommended Improvements
are shown in Bold
®
^ T r
-I
i
W11-1
SHARE
THE
ROAD
W16-1
NOT TO SCALE
REV. 3/10/2009 N:\)874\Figurai\LLCia74 Rgure 8-1
LINSCOTT
LAW &
GREENSPAN
e ng ia ee rs
Figure 8-1
Recommended Mitigation Measures
ENCINAS CREEK BRIDGE