TO: HONORABLE MAYOR AND MEMBERS OF THE CITY COUNCIL
FROM: Bob Moehling, Public Works Director
PREPARED BY: Jeff Hitch, City Engineer
SUBJECT:
title
Los Alamos Traffic Congestion Pilot Program
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RECOMMENDATION
recommendation
Receive and file.
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PRIOR ACTION/VOTE
None.
CITY COUNCIL GOAL
Plan, program and create infrastructure development.
DISCUSSION
On December 3, 2024, the City Council requested staff to scope a Traffic Congestion Pilot Program. Staff returned to City Council on January 21, 2025, with a proposed Traffic Pilot Program designed to reduce traffic congestion on a limited scale, specifically in the Los Alamos corridor between Hospitality Lane and Whitewood Road. The program was established with four main steps:
1. Traffic Counts
Existing traffic counts were established in Fall 2024. Staff worked with Caltrans to implement optimized timing to work with the Caltrans-maintained signals at the I-215 interchange.
2. Perform “Before” Travel Time Runs
“Before” travel time runs were established, identifying travel time, stops, and delays for the corridor during peak periods: morning, midday, and evening, to serve as the baseline for the program.
3. Traffic Observation/Signal Timing Adjustment
Traffic needed to be observed and timing adjusted through the corridor from the City’s Traffic Management Center (TMC). Existing traffic cameras were previously installed at the intersections of Hancock Avenue and Whitewood Road. Staff added cameras at the intersection of Monroe Avenue and Lincoln/Vista Murrieta. The cameras were used to observe traffic at various times of day across different intersections to identify potential traffic disruptions.
4. Perform “After” Travel Time Runs
After the observation period, travel time runs were performed during the same peak time periods. The results of the travel runs are presented below.
On November 14, 2025, staff provided an update to City Council.
• Cameras at Monroe and Lincoln/Vista Murrieta were installed.
• The pavement rehabilitation project on Los Alamos Road, from Lincoln/Vista Murrieta to Whitewood Road, was recently substantially completed, though loops had not yet been reinstalled.
• As part of the pavement rehabilitation project, dual left turns were added for westbound Los Alamos Road to southbound Hancock Avenue to help with queuing in that intersection.
• The cycle length was changed from 110 to 120 seconds, with updated timing files sent to Caltrans for approval and implementation. Left-turn movements at both I-215 intersections were requested to be changed from “lag” to “lead” to reduce delay.
Travel Runs
The “Before” travel runs were taken in the AM, midday, and PM peak hours in April 2025, and the “After” travel runs in February 2026. The reported times are only for the direction of coordinated traffic flow. Traffic signal coordination synchronizes consecutive traffic signals along a corridor to allow “platoons” of vehicles to move through green lights with fewer stops and reduced delay, typically at or near the speed limit. Common side effects include potentially increased waiting times on side streets and additional delay in the opposite direction of the coordination. The results of the travel runs are as follows:
|
|
“Before” Apr 2025 |
“After” Feb 2026 |
Change |
% Change |
|
AM (West Bound) |
294 sec |
245 sec |
-49 sec |
-17% |
|
Midday (West Bound) |
182 sec |
178 sec |
-4 sec |
-2% |
|
PM (East Bound) |
632 sec |
243 sec |
-389 sec |
-62% |
Conclusion
The Pilot Program resulted in an overall decrease in travel time along the Los Alamos Road corridor when travelling in the direction of coordinated traffic. The recent multi-family residential developments along the corridor led to increased congestion, warranting changes to reduce delay. The improvements included:
• Updated traffic timing with the Caltrans ramp signals at I-215;
• Increasing the cycle length to 120 seconds;
• Changing the left-turn movements at both I-215 ramp intersections from lag to lead; and
• Adding dual left turns at westbound Los Alamos Road to southbound Hancock Avenue.
Traffic staff routinely review the traffic coordination of each arterial roadways on a three- to four-year cycle, or as conditions change that might warrant adjustments. Staff is anticipating reviewing the California Oaks Road corridor next. The Murrieta Hot Springs Road corridor will be addressed after the current widening project is completed.
While the revised traffic signal timing decreased travel run times on Los Alamos, staff did not study any corresponding loss of travel run time on north/ south roadways intersecting Los Alamos.
FISCAL IMPACT
There is no fiscal impact associated with the recommended action.
ATTACHMENTS
None.