Development and Implementation of Coordinated Adaptive Ramp Metering (CARM) in Southern California Interstates for Congestion Mitigation

The goal of this proposed Coordinated Adaptive Ramp Metering (CARM) implementation project is to mitigate congestion and improve traffic flow along the interstate I-15 corridor in the Southern California region. This advanced traffic management system aims to optimize freeway operations by dynamically adjusting ramp metering rates based on real-time traffic conditions across the entire I-15 corridor. By implementing CARM, the project seeks to increase average speeds, reduce travel times, enhance safety, and improve overall traffic efficiency. The existing ramp metering approach at key on-ramps such as Magnolia Ave, Ontario Ave, El Cerrito Road, and Cajalco Road lacks automatic responsiveness to crashes and lane-blocking events, coordination across multiple ramps, and optimal queue distribution to increase corridor throughput[1].

To address these issues, a Coordinated Adaptive Ramp Metering (CARM) system is proposed. CARM is an advanced traffic management strategy that dynamically adjusts ramp metering rates based on real-time traffic conditions across an entire freeway corridor[2]. This system aims to optimize freeway operations by a) Coordinating multiple ramp meters to work together, balancing the flow of vehicles entering the freeway b) Using centralized adaptive algorithms to analyze data from the entire corridor and adjust metering behavior accordingly c) Maximizing freeway throughput while minimizing queues on the ramps d) Responding in real-time to traffic incidents and congestion.

The project will implement the following objectives- (1) Develop and implement a CARM system on I-15 southbound between SR-91 and Cajalco Road to reduce PM peak period congestion by automatically adjusting metering rates in response to real-time traffic conditions, including crashes and lane-blocking events. (2) Optimize ramp metering algorithms to distribute queues across multiple on-ramps (Magnolia Ave, Ontario Ave, El Cerrito Road, and Cajalco Road) to increase overall corridor throughput during peak periods.

USDOT Priorities:

The USDOT Strategic Plan for FY 2022-2026 prioritizes strategies that improve system operations to increase travel time reliability, manage travel demand, and improve connectivity. This project directly aligns with those strategies by promoting the adoption of transportation management and operations (TSMO) practices. Also, this project improves travel time reliability on congested corridors. This project is aligned with Objective 1 of MCEEST’s goals - Create a safer, more reliable, and more resilient transportation system that improves equity through increased access to jobs, housing, services, and other opportunities for historically underserved communities. Interstate 15 in the San Bernardino and Riverside counties in California passes through historically disadvantaged communities. The congestion on I-15 is a major reason why these communities have difficulties accessing jobs and services.