TC - Item 3C - Traffic Review of Signage and Markings on San Gabriel Boulevard Near Hellman Avenue and the EB 1-10 Fwy on-ramp
ROSEMEAD TRAFFIC COMMISSION
STAFF REPORT
TO: TRAFFIC COMMISSION
FROM: CHRIS DASTÉ, DIRECTOR OF PUBLIC WORKS
DATE: MARCH 11, 2021
SUBJECT: TRAFFIC REVIEW OF SIGNAGE AND MARKINGS ON SAN GABRIEL
BOULEVARD NEAR HELLMAN AVENUE AND THE EB I-10 FREEWAY
ON-RAMP
SUMMARY
On behalf of the City of Rosemead, engineering staff completed a traffic review and recommended
appropriate measures to improve and evaluate the existing signage located on San Gabriel
Boulevard for northbound travel as drivers approach Hellman Avenue and the EB 1-10 Freeway
On-Ramp. The current signage on San Gabriel Boulevard provides lane designations for the
freeway on-ramp and other roads, however the current signage as is, is not clear and makes it
difficult for motorists to understand and maneuver into the correct lanes, especially as drivers drive
NB approaching the Hellman Avenue intersection and the EB 1-10 On-Ramp. Due to the on-
ramp’s proximity to the intersection of Hellman Avenue on San Gabriel Boulevard, signs have
been installed showing lane designations, however the signs show as if there are 2 lanes making a
right onto the freeway. Clarification of the lane designations exist with text below the right turn
arrows; however, the writing is small.
Please note that this intersection appears to be within Caltrans jurisdiction and may require
coordination between the City and Caltrans to facilitate any improvements. If the recommended
improvements are approved, City Staff would need to initiate the coordination efforts with Caltrans
to implement the below recommended improvements.
ANALYSIS
The traffic review included an analysis of the existing roadway conditions and evaluation on ways
to make the lane designations clearer for the motorists, this included a review of existing signage
and pavement legends as well as a review of approximately 5 years of available collision data.
This location is within the City of Rosemead however it appears that the subject intersection may
be under Caltrans jurisdiction. San Gabriel Boulevard is a north/south principal arterial roadway.
San Gabriel Boulevard is approximately 75-feet wide, with two lanes in each direction separated
by a median created by two solid yellow lines. As San Gabriel Boulevard approaches the
intersection with Hellman Avenue, two lanes become four lanes, with a left turn lane and an
City Traffic Commission Meeting
March 11, 2021
Page 2 of 3
exclusive right turn lane to Hellman Avenue added. The right turn lane is strictly for right turns
onto Hellman Avenue. The lane designated by the sign as a shared right and through lane on San
Gabriel Boulevard is indicating that the lane passes through the intersection of Hellman Avenue,
and immediately north of the intersection this lane can either enter onto the I-10 Eastbound Ramp
or stay on San Gabriel Boulevard. This is represented in the attached picture summary. San Gabriel
Boulevard has a posted speed limit of 35 mph. San Gabriel Boulevard carries approximately
35,150 vehicles per day (both directions). The 2018/2019 intersection data also found in the Long
Range Plan that for existing conditions approximately 1,000 to 1,200 vehicles are continuing
through the intersection in the northbound direction. What this shows is that without adequate
advance signage vehicles will be unable to find a gap in through traffic to merge to the right to
enter the I-10 EB On-Ramp.
Collision data was obtained from the computerized collision records system maintained by the
State of California called the Statewide Integrated Traffic Records Systems (SWITRS). A review
of all collisions that occurred along San Gabriel Boulevard for vehicle traveling NB within 100-
feet of the Eastbound I-10 Ramps was conducted over a 5-year period between January 2016 to
the most recent available accident data, December 2020. Per the review of the collision history,
there were 7 collisions over the last 5 year period that involved NB traffic. Overall, the intersection
had a total of 19 collisions over this same period, however since the area of concern is the NB
traffic getting onto the I-10 EB On-Ramp only those impacting the NB movements was recorded.
STAFF RECOMMENDATION
After a thorough review of the area and analysis of the existing conditions, the study concluded
that the signage along San Gabriel Boulevard approaching the I-10 EB On Ramp would benefit
from additional traffic signage to allow motorists to select the appropriate lane before reaching the
end of the line of waiting vehicles. These improvements will aid in making the lane designations
more visible in advance of the freeway on-ramp and right turn only to Hellman Avenue before
motorists get to the end of the line of waiting vehicles.
This intersection appears to be within Caltrans jurisdiction and may require coordination between
the City and Caltrans to facilitate any improvements. It is recommended that City Staff initiate
these coordination efforts with Caltrans to implement the below recommended improvements.
A detailed traffic report and proposed figure diagram is attached as Attachment A to this staff
report, please refer to Figure 4 of Attachment A for the properad diagram.
Below is a detailed list of the recommendations:
1. Remove the existing signage on San Gabriel Boulevard NB on the Mast Arm and the
approach to the intersection and replace with larger signs (54x45) for Multi-Lane Roads
per CAMUTCD 2B.19. To make the sign easier for motorists to read the lane designations,
it is recommended to add the RT Lane and I-10 symbol below the Thru/RT lane and ONLY
HELLMAN below the right turn arrow on the sign per CAMUTCD 2B.19-20. The
City Traffic Commission Meeting
March 11, 2021
Page 3 of 3
approach sign should be moved to the start of the right turn only lane (150’ to 300’ in
advance).
2. Re-paint Right Arrow Pavement Legend on right-only lane along San Gabriel Boulevard
according to Figure 4. This includes adding the Pavement Legend “ONLY” approximately
90-feet before Hellman Avenue, directly under the RT ARROW to say “ONLY” Legend,
to indicate to drivers this lane is only for turning onto Hellman Avenue.
3. Install and add Pavement Legends indicated by a Through and Straight Arrow and add the
I-10 Freeway icon underneath as shown in Figure 4. This includes adding two “Through
and Straight Arrows with the I-10 Frwy Icon” Legends at two locations along San Gabriel
Boulevard - approximately 10-feet south of Hellman Avenue and again approximately 80-
feet south of Hellman Avenue as shown in Figure 4.
4. Install lane line extension through the intersection (per detail 40 of the CAMUTCD) for
the right turning lane to Hellman Avenue to help guide vehicles to making the right onto
Hellman Avenue.
Prepared by:
Jana Robbins, Contract Traffic Engineering Division
Attachments:
A. Technical Engineering Report: Traffic Review of Signage and Markings on San
Gabriel Boulevard Near Hellman Avenue and the Eb I-10 Freeway On-Ramp
B. Courtesy Notice to Residents
CITY OF ROSEMEAD
Prepared By: Transtech Engineers, Inc. | Page 1 of 7
TO: Chris Dasté, Director of Public Works
FROM: Traffic Engineering, Transtech Engineers, Inc.
DATE: January 22, 2021
SUBJECT: TRAFFIC REVIEW OF SIGNAGE AND MARKINGS ON SAN GABRIEL BOULEVARD NEAR
HELLMAN AVENUE AND THE EB I-10 FREEWAY ON-RAMP
JN#: 201230
INTRODUCTION/BACKGROUND
On behalf of the City of Rosemead, engineering staff has completed a traffic review and recommended
appropriate measures to improve and evaluate the existing signage located on San Gabriel Boulevard for
northbound travel as drivers approach Hellman Avenue and the EB 1-10 Freeway On-Ramp. The current
signage on San Gabriel Boulevard provides lane designations for the freeway on-ramp and other roads,
however the current signage as is, is not clear and makes it difficult for motorists to understand and
maneuver into the correct lanes, especially as drivers drive NB approaching the Hellman Avenue
intersection and the EB 1-10 On-Ramp. Due to the on-ramp’s proximity to the intersection of Hellman
Avenue on San Gabriel Boulevard, signs have been installed showing lane designations, however the signs
show as if there are 2 lanes making a right onto the freeway. Clarification of the lane designations exist
with text below the right turn arrows; however, the writing is small. The traffic review included an analysis
of the existing roadway conditions and evaluation on ways to make the lane designations clearer for the
motorists, this included a review of existing signage and pavement legends as well as a review of
approximately 5 years of available collision data. Please refer to Figure 1 below for a vicinity map of the
subject location.
Figure 1: Vicinity Map
I-10 Freeway San Gabriel Blvd S Walnut Creek Grove Del Mar Ave Hellman Ave
LEGEND Area of Interest: Signage on San Gabriel Boulevard Approaching
Hellman Avenue and the Eastbound I-10 Freeway On-Ramp
TRAFFIC REVIEW OF SIGNAGE AND MARKINGS ON SAN GABRIEL BOULEVARD NEAR HELLMAN AVENUE AND THE EB I-10 FREEWAY ON-RAMP
CITY OF ROSEMEAD
Prepared By: Transtech Engineers, Inc. | Page 2 of 7
Figure 2: Existing Conditions
EXISTING SIGNAGE AND PAVEMENT LEGENDS
SExisting Signage for Northbound Travel at
intersection of San Gabriel Blvd and Hellman Ave
(Signage on NB Mast Arm)
Arial view of the intersection of San Gabriel Blvd and Hellman
Ave (Pavement Legends in Right and Thru Lanes NB). The NB
lanes show no pavement arrows for the 1st thru lane which leads
to the On-Ramp.The Exclusive Right Lane has an ONLY under the
Right Turn Arrow.
LEGEND
Signage of Interest
Area of Confusion for the I-10
Eastbound Ramp
Existing Lane Designation Sign
Indicating that the Right turn
lane ONLY and the Shared
Thru and RT lane has a small
10 FRWY EAST underneath
Right Lane Must Turn Right
(R3-7) Sign
35-MPH Speed Limit (R2-1)
Sign
Stop (R1-1) Sign
Not A Through Street Sign San Gabriel Blvd Hellman Ave
Hellman Ave San Gabriel Blvd
TRAFFIC REVIEW OF SIGNAGE AND MARKINGS ON SAN GABRIEL BOULEVARD NEAR HELLMAN AVENUE AND THE EB I-10 FREEWAY ON-RAMP
CITY OF ROSEMEAD
Prepared By: Transtech Engineers, Inc. | Page 3 of 7
EXISTING ROADWAY CONDITIONS
San Gabriel Boulevard: Within the City of Rosemead, San Gabriel Boulevard is a north/south principal
arterial road. San Gabriel Boulevard is approximately 75-feet wide, with two lanes in each direction
separated by a median created by two solid yellow lines. As San Gabriel Boulevard approaches the
intersection with Hellman Avenue, two lanes become four lanes, with a left turn lane and an exclusive
right turn lane to Hellman Avenue added. The right turn lane is strictly for right turns onto Hellman
Avenue. The lane designated by the sign as a shared right and through lane on San Gabriel Boulevard is
indicating that the lane passes through the intersection of Hellman Avenue, and immediately north of the
intersection this lane can either enter onto the I-10 Eastbound Ramp or stay on San Gabriel Boulevard.
This is represented in the attached picture summary. San Gabriel Boulevard has a posted speed limit of
35 mph. San Gabriel Boulevard carries approximately 35,1501 vehicles per day (both directions). The
2018/2019 intersection data also found in the Long Range Plan that for existing conditions approximately
1,000 to 1,200 vehicles are continuing through the intersection in the northbound direction. What this
shows is that without adequate advance signage vehicles will be unable to find a gap in through traffic to
merge to the right to enter the I-10 EB On-Ramp.
1 Source: Long Range 2040 City-Wide Traffic Analysis, January 2019
This photos shows anotehr view of the northbound
intersection of San Gabriel Blvd and Hellman Ave, as seen in
this photo the lane designation signage is hard to read as
an approaching car. The sign appears to show that 2 right
turn lanes enter the freeway On Ramp.
This photo shows the northbound view of intersection of
San Gabriel Blvd and Hellman Ave, as seen in this photo the
NB lanes show no pavement arrows for the 1st thru lane
which leads to the On-Ramp legend and can cause
confusion for approaching vehicles attempting to merge
onto the I-10 Freeway.
TRAFFIC REVIEW OF SIGNAGE AND MARKINGS ON SAN GABRIEL BOULEVARD NEAR HELLMAN AVENUE AND THE EB I-10 FREEWAY ON-RAMP
CITY OF ROSEMEAD
Prepared By: Transtech Engineers, Inc. | Page 4 of 7
PICTURE SUMMARY: EXISTING CONDITIONS
COLLISION INVESTIGATION
Collision data was obtained from the computerized collision records system maintained by the State of
California called the Statewide Integrated Traffic Records Systems (SWITRS). A review of all collisions that
occurred along San Gabriel Boulevard for vehicle traveling NB within 100-feet of the Eastbound I-10
Ramps was conducted over a 5-year period between January 2016 to the most recent available accident
data, December 2020. Table 1 provides a detailed list of these collisions within 100-feet of the Eastbound
I-10 Ramps along San Gabriel Boulevard.
Northbound at intersection of San Gabriel Blvd and
Hellman Ave
Northbound along San Gabriel Blvd toward EB I-10
Ramp
Northbound Signage Approaching the Intersection
of San Gabriel Blvd and Hellman Ave (grafitti on
sign)
TRAFFIC REVIEW OF SIGNAGE AND MARKINGS ON SAN GABRIEL BOULEVARD NEAR HELLMAN AVENUE AND THE EB I-10 FREEWAY ON-RAMP
CITY OF ROSEMEAD
Prepared By: Transtech Engineers, Inc. | Page 5 of 7
Table 1: Summary of Collision History Included Only Those Collisions involving NB Traffic
No. Location Dist. Date Collision
Type
PCF Severity Factor
1 SAN GABRIEL BL
AT HELLMAN AV 117’N 7/1/18 REAR END UNSAFE
SPEED INJURY NB THRU VEH HIT NB THRU VEH AND NB
THRU VEH
2 HELLMAN AV AT
SAN GABRIEL BL 0’ 8/4/17 BROADSIDE STOP
SGN|SIG PDO NB THRU VEH HIT WB THRU VEH
3 SAN GABRIEL BL
AT HELLMAN AV 0’ 4/20/17 SIDESWIPE STOP
SGN|SIG INJURY EB THRU VEH HIT NB THRU VEH
4 SAN GABRIEL BL
AT HELLMAN AV 160’S 9/8/17 SIDESWIPE IMPROP
TURN PDO NB RGT TURN VEH HIT NB PARKED VEH
5 SAN GABRIEL BL
AT HELLMAN AV 0’ 4/8/16 BROADSIDE UNKNOWN PDO EB THRU VEH HIT NB THRU VEH
6 SAN GABRIEL BL
AT HELLMAN AV 58’S 4/14/16 HEAD-ON R-O-W
AUTO INJURY SB THRU VEH HIT NB STOPPED VEH
7 SAN GABRIEL BL
AT HELLMAN AV 25’N 10/17/16 BROADSIDE R-O-W
AUTO PDO NB ENT TRAF VEH HIT NB THRU VEH
Per the review of the collision history, there were 7 collisions over the last 5 year period that involved NB
traffic. Overall, the intersection had a total of 19 collisions over this same period, however since the area
of concern is the NB traffic getting onto the I-10 EB On-Ramp only those impacting the NB movements
was recorded. Refer to Figure 3 for a diagram of NB collisions within 100-feet of the Eastbound I-10 Ramps
along San Gabriel Boulevard.
Figure 3: Collision Diagram
TRAFFIC REVIEW OF SIGNAGE AND MARKINGS ON SAN GABRIEL BOULEVARD NEAR HELLMAN AVENUE AND THE EB I-10 FREEWAY ON-RAMP
CITY OF ROSEMEAD
Prepared By: Transtech Engineers, Inc. | Page 6 of 7
RECOMMENDATIONS
After a thorough review of the area and analysis of the existing conditions, the study concluded that the
signage along San Gabriel Boulevard approaching the I-10 EB On Ramp would benefit from additional
traffic signage to allow motorists to select the appropriate lane before reaching the end of the line of
waiting vehicles. These improvements will aid in making the lane designations more visible in advance of
the freeway on-ramp and right turn only to Hellman Avenue before motorists get to the end of the line of
waiting vehicles.
This intersection appears to be within Caltrans jurisdiction and may require coordination between the City
and Caltrans to facilitate any improvements. It is recommended that City Staff initiate these coordination
efforts with Caltrans to implement the below recommended improvements.
Recommendations
1. Remove the existing signage on San Gabriel Boulevard NB on the Mast Arm and the approach to the
intersection and replace with larger signs (54x45) for Multi-Lane Roads per CAMUTCD 2B.19. To make
the sign easier for motorists to read the lane designations, it is recommended to add the RT Lane and
I-10 symbol below the Thru/RT lane and ONLY HELLMAN below the right turn arrow on the sign per
CAMUTCD 2B.19-20. The approach sign should be moved to the start of the right turn only lane (150’
to 300’ in advance).
2. Re-paint Right Arrow Pavement Legend on right-only lane along San Gabriel Boulevard according to
Figure 4.
a. Add Pavement Legend “ONLY” approximately 90-feet before Hellman Avenue, directly under
the RT ARROW to say “ONLY” Legend, to indicate to drivers this lane is only for turning onto
Hellman Avenue.
3. Add Pavement Legend indicated by a Through and Straight Arrow and add the I-10 Freeway icon
underneath as shown in Figure 4.
RT LANE
ONLY
HELLMAN
TRAFFIC REVIEW OF SIGNAGE AND MARKINGS ON SAN GABRIEL BOULEVARD NEAR HELLMAN AVENUE AND THE EB I-10 FREEWAY ON-RAMP
CITY OF ROSEMEAD
Prepared By: Transtech Engineers, Inc. | Page 7 of 7
b. Add two “Through and Straight Arrows with the I-10 Frwy Icon” Legends at two locations
along San Gabriel Boulevard - approximately 10-feet south of Hellman Avenue and again
approximately 80-feet south of Hellman Avenue as shown in Figure 4.
4. Install lane line extension through the intersection (per detail 40 of the CAMUTCD) for the right
turning lane to Hellman Avenue to help guide vehicles to making the right onto Hellman Avenue.
Figure 4. Recommendations Aerial View
LEGEND San Gabriel Blvd Hellman Ave
Proposed Larger Sign: Curve (R73-1) sign +
straight arrow (R3-5) sign + Right Only
Arrow (R3-8) Sign
Re-paint existing “Right Arrow” legend
Lane tracking
ONLY
ONLY Install “ONLY” Legend below each RT
Arrow
Install Through RT Arrow with I-10
Freeway Icon 10’ 80’ ONLY
ICON
ICON
Traffic Commission Courtesy Notification
NOTICE IS HEREBY GIVEN that on Thursday, February 4, 2021, at the hour of 7:00 p.m., or soon thereafter as the matter may be heard,
the Rosemead Traffic Commission will hold a public meeting in the Council Chambers at City Hall for the purpose of reviewing the Traffic
Conditions at the intersection of San Gabriel Boulevard at Hellman Avenue.
To adhere to the Los Angeles County Health Officer’s, updated June 11, 2020, Revised Safer at Home Order, this meeting will be held via
teleconference and the public will have access to observe the meeting telephonically by calling 1 (267) 866-0999, Code ID: 6163-10-9205
or visit www.cityofrosemead.org to watch online. Please note that, in accordance with Governor Newsom’s Executive Order N-29-20 and
N-35-20, there will not be a physical location from which the public may attend.
You are being notified of this meeting because your property is within proximity to the location. We encourage your comments regarding
traffic safety in this area. Citizens’ wishing to comment may do so by calling (626) 569-2100 or via email at
publiccomment@cityofrosemead.org by 5:00 p.m. Please identify the topic you wish to comment in your email’s subject line. All comments
are public record and will be recorded in the official record of the City. Written comments must be addressed to:
City of Rosemead
Public Works Department
8838 E. Valley Boulevard
Rosemead, California 91770
Attention: Mr. Chris Dastè, Director of Public Works
Again, only comments received by 5:00 p.m. on Thursday, February 4, 2021, will be accepted. We appreciate your concern for traffic safety
in the City of Rosemead. Should you have any questions regarding this letter, please contact the Director of Public Works, Chris Dastè at
626-569-2158.
For information please call:
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626-569-2150
Proposed Conditions for San Gabriel Boulevard at Hellman Avenue