Rosalva Ureno, PE, TE
Transportation Manager/City Traffic Engineer
Aaron M. Cox, PE, TE, PMP
Senior Traffic Engineer
April 2, 2025
The Ask:
That the City Council provide direction to implement
and investigate treatments that can improve the traffic operations along Magnolia Avenue at El Sobrante Road.
Magnolia Ave
INTERSTATE 15
Corridor Operations
• Multiple Agencies – Caltrans operates the ramp signals while City of Corona operates the adjacent intersections
• Competing Objectives – Caltrans prioritizes freeway flow, while the City wants to keep Magnolia moving
• Geometry – Proximity of El Sobrante to the I-15 SB Ramp is ~75 feet
• Control – City has no visibility into how the Caltrans ramp signals are operating. Caltrans has proprietary software that does not interface with our Advanced Traffic Management System. We rely on their clocks being synchronized to GPS time
• Volumes – 2
nd busiest corridor in the City along with the heavy
demand of I-15 freeway traffic
Typical Weekday PM Conditions
El Sobrante Rd at Magnolia Ave
This option maintains full access to and from El Sobrante Avenue, while removing the westerly Magnolia Ave crosswalk.
Removal of this crosswalk facilitates better signal timing coordination for the Magnolia Corridor.
This option would remove the signalized intersection at El Sobrante Rd and Magnolia Ave. and would allow right turn movements in/out of the shopping center as well as El Sobrante Rd. By eliminating the left turns and through movements at this location, additional vehicle storage and more efficient signal timing could be realized.
This option would completely close the El Sobrante Road before intersecting Magnolia Avenue, convert the shopping center to limited access. This option would eliminate the signal at El Sobrante leading to additional vehicle storage, more efficient signal timing, and less conflicting movements.
Short Term
This option is a near term improvement that
would result in operational improvements for
the Magnolia Corridor.
• Delay Improvements - Vehicle timing
substantially shorter than the pedestrian
crosswalk timing required
• Each pedestrian actuation delays up to
30 seconds, and can put the intersection
in transition for up to 6 minutes
• Pedestrian delay to use Rimpau Ave
crosswalk
9 Pedestrians vs 3600 Vehicles
during highest Peak Hour at the
El Sobrante / Magnolia Intersection
Long Term – Option A
• Signal Coordination improvements with
signal at El Sobrante removed
• Additional vehicle storage for more
efficient movements
• Less delays, more corridor throughput
• Reduced Access to El Sobrante and
shopping center
• Detoured Traffic – Route traffic to
Rimpau or El Camino
This option would remove the signalized intersection
at El Sobrante Rd and Magnolia Ave and restrict left
turn movements in and out of the shopping center as
well as El Sobrante Rd.
Long Term – Option B
This option would remove the signalized intersection
at El Sobrante Rd and Magnolia Ave and allow right
turn movements in and out of the shopping center
with access to El Sobrante Rd closed off.
• Signal coordination improved with signal
removed
• Less conflict points (Safer)
• Additional vehicle queuing storage for more
efficient movements
• Even less delays, more corridor throughput
• Opportunity to beautify “dead space”
• Reduced access to El Sobrante and Shopping
Centers
• Detoured Traffic – Use Rimpau or El Camino
• Introduce cut-through route through business
• Emergency access concerns
01 02
03 Short Term
Option
Long Term
Option A
Long Term
Option B
Concurrence on removal of westerly crosswalk at El Sobrante and Magnolia to improve signal coordination for the Magnolia Avenue Corridor
Direction to study the conversion of El Sobrante and Shopping Center entrances to a limited access configuration including the removal of the traffic signal at El Sobrante at Magnolia Direction to study the conversion of Shopping Center entrance to a limited access configuration, removal of the traffic signal at El Sobrante at Magnolia and removal of access to El Sobrante Road from Magnolia Avenue
The Ask:
That the City Council provide direction to implement
and investigate treatments that can improve the traffic operations along Magnolia Avenue at El Sobrante Road.
Magnolia Ave
INTERSTATE 15