I-15 Comprehensive Corridor Study
The Interstate 15 corridor is the main transportation connection between the Los Angeles metropolitan area and the high desert, Las Vegas, Rocky Mountain states and the Midwest. It is also an important link to Riverside and San Diego counties to the south. Currently, I-15 is congested during weekday peak commuting hours and on weekends and holidays.
The Southern California Association of Governments, San Bernardino Associated Governments, the Riverside County Transportation Commission and Caltrans jointly sponsored a study to evaluate transportation needs on Interstate 15 from Route 60 near Ontario to the Mojave River in Victorville. While all types of travel were considered, the study focused on truck and large recreational vehicle transportation issues. The study was completed in December 2005 and will help define how this 45-mile section of I-15 should be improved to meet current and future traffic demands.
What did the I-15 study involve?
The study began in mid-2003. Traffic studies were conducted to document existing conditions, and forecasts of future traffic were created to help plan for future improvements. A public outreach effort in spring 2004 generated 500 survey responses from I-15 users to help document perceptions of travel along this freeway. The surveys showed that the greatest concern was the I-15/I-215 interchange in Devore, a major bottleneck. Other problems were cited as well: heavy congestion on I-15 between Route 60 and Route 210, safety concerns in the Cajon Pass and the heavy volume of trucks mixing with auto traffic.
Options for Improvement
Based on the problems identified, a series of alternatives was developed and evaluated. Five alternatives —of which also include improvements to the I-15/I-215 interchange — were studied in greater detail. These included:
- Alternative A — The “no build” alternative. The study will define what would happen if there were no new improvements
- Alternative B — The “transportation system management” alternative. No lanes would be added to I-15, but changes would be made to improve merging to and from the freeway, expand bus service in the corridor, enhance safety, and reduce delays from accidents.
- Alternative C — The “high occupancy vehicle” alternative. One new lane for carpools and buses only would be added in each direction from Route 60 to the Mojave River. The cost of this alternative ranges from $500 million to $700 million.
- Alternative D — The “exclusive truck lane” alternative. Two new lanes for trucks only would be added in each direction from Route 60 to the Mojave River. The lanes would be separate from auto traffic. Trucks would enter and exit these lanes only at major freeway interchanges and near industrial areas. Double-decking of I-15 may be needed in a few sections of I-15 to fit in the lanes, but in most locations the lanes would be in the middle of the freeway between the northbound and southbound lanes. The cost of this alternative ranges from $2 billion to $3.5 billion.
- Alternative E — The “reversible lane” alternative. Two new lanes would be built from Route 210 to U.S. 395, separate from the existing lanes. The lanes would run southbound in the morning commute hours and northbound in the evening commute hours. At other times, the lanes would serve the heaviest flow of traffic. In addition, at least one lane in each direction would be added south of Route 210 and north of U.S. 395. The cost of this alternative ranges from $600 million to $800 million.
The I-15 policy committee recommended two alternatives be carried forward for further corridor development efforts. These included:
- Alternative D (dedicated truck lanes) – Construction of two dedicated truck lanes in each direction for the full length of the study corridor, with access only at key interchanges. The cost is estimated to be between $2 billion and $3.5 billion. Most of the funding must come from user-based sources. Two sub-options should be considered:
- With provision for longer combination vehicles (LCVs)
- Without provision for LCVs
- Alternative C/E hybrid (reversible lanes from SR-210 to U.S. 395 with HOV lanes north and south of the reversible lanes) - The cost is estimated to range between $600 and $800 million. Tolls would likely be charged in the reversible lane portion of the corridor, yielding partial funding of the reversible lane section between U.S. 395 and SR-210.
- Reconfigure the I-15/I-215 interchange under all options
- Implement transportation system management and traffic demand management strategies under all options
The I-15 Comprehensive Corridor Study Final Report that documents the study results and the recommendation endorsed by the policy committee in April 2005.
The I-15 TAC reviewed and accepted the report, with the proviso that a stronger statement be made about the importance of moving forward with improvements to the I-15/I215 interchange. The need to improve this interchange was the most frequent comment received during the public outreach efforts, and the interchange will need to be improved regardless of the ultimate strategy selected for other parts of the corridor. The TAC specifically recommended that the initiation of a Project Study Report or combined Project Study Report/Project Report for the I-15/I-215 interchange should be a primary goal for the 2006-2007 fiscal year. The recommended configuration includes the following elements:
- Reconfigure the interchange to establish I-15 as the primary movement by providing four through-lanes on I-15 in each direction through the interchange.
- Provide truck bypass lanes on I-15 through the interchange to minimize the impact of truck traffic and to reduce the potential for conflict between trucks and other traffic entering/ exiting I-15 to I-215.
- Preserve the ability to implement future corridor improvements through the interchange with minimal need to modify the reconfigured interchange and associated structures.
The Final Report describes specific steps that could be taken to advance the I-15/I-215 project. The report acknowledges that funding of this interchange improvement will need to be considered with other improvement priorities as part of the Strategic Plan for Measure I 2010-2040 but emphasizes that the interchange is an essential part of maintaining mobility for both San Bernardino Valley and Victor Valley residents. The expenditure plan for Measure I 2010-2040 allocates three percent of the revenue from the San Bernardino Valley and the Victor Valley subareas to improvements in the Cajon Pass. The I-15/I-215 interchange would be a candidate for the use of these funds.
Director of Planning
Phone: (909) 884-8276