Solving Gridlock on Major Los Angeles Freeways

October 24, 2016

Michael Baker International Identifies Improvements to Reduce Major Traffic Hot Spots in LA 

It’s no secret that Los Angeles County residents face significant daily challenges caused by mind-numbing traffic congestion on LA freeways. Based on Michael Baker International’s record of success designing highway infrastructure that reduces congestion, improves safety and operations and minimizes environmental impact, the Los Angeles County Metropolitan Transportation Authority (Metro) awarded the firm a $7.6M contract to identify improvements on a particularly choked three-mile stretch of freeway and complete the environment phase of work. A previous feasibility study of 40 miles of congested freeway across the I-605, SR-91 and I-405 corridors completed by Michael Baker identified this particular site as a key freeway hot spot.
Approximately 270,000 vehicles travel the westbound SR-91 each day.

The project spans westbound SR-91 from the vicinity of Shoemaker Avenue to the I-605/SR-91 interchange, a distance covered by 270,000 vehicles a day. It also includes improvements to the Norwalk, Pioneer and Bloomfield local interchanges within the Gateway Cities, a 200-square mile, 15-community region in the southeast area of Los Angeles County, and home to approximately two million people.
The Gateway Cities sub-region, frequently called the “epicenter of transportation planning" provides: access to global trade via two of the world’s leading full-service seaports; a recently upgraded commercial service airport; rail yards that transport ever-increasing amounts of imports and exports; and a complex network of roads and public transportation.
The significant congestion on the I-605/SR-91 system interchange is expected to increase in the future as a result of these factors if physical and operational improvements aren’t made to the roadways. 
History of Partnership
In 2011, Metro selected Michael Baker to analyze congestion and improvements needed for traffic hot spots along more than 40 miles of I-605, I-405 and SR-91 freeways in Los Angeles County. The completed SR-91/I-605/I-405 Congestion Hot Spots Feasibility Study incorporated 19 different traffic-model scenarios and included the Michael Baker team’s analyzed improvements to five freeway-to-freeway system interchanges, 35 local arterial street interchanges, mainline freeway general purpose lanes, HOV direct connectors and arterial improvements through numerous cities.
The firm’s successful completion of the $5.7M feasibility study and its thorough knowledge of the corridor’s issues and challenges prompted Metro to exercise a contract option with Michael Baker to prepare additional study documents for two of the major system interchanges at I-605/SR-91 and I-605/I-5. These Project Study Report-Project Development Support (PSR-PDS) documents included traffic modeling, analysis and geometric plans for 20 miles of freeway widening for three separate alternatives, including concept cost estimates.  An initial phasing analysis to identify potential-phased improvements also was performed given the limited funding available to implement the full improvement program.
Widening SR-91 will improve overall freeway operations in the region.

These PSR-PDS documents provided a critical step in identifying the capital outlay needed to complete the engineering and environmental technical studies required for the subsequent Project Approval phase (PA/ED) and fostered consensus on the purpose, need, general scope and schedule of the project. The PSR-PDS phase of the project was completed in July 2014.
Hot Spot on Westbound SR-91
Metro and the Gateway Cities Council of Governments ultimately determined that an initial phase of the larger I-605/SR-91 improvement project would be the westbound SR-91 from Shoemaker Avenue to the I-605/SR-91. The Michael Baker team identified that the congestion in this area is the result of insufficient SR-91 freeway mainline capacity, inadequate capacity of the existing two lane connector for the westbound SR-91 to northbound and southbound I-605, and closely spaced freeway entrance and exit ramps. The existing freeway also experiences high concentrations of accidents.
Michael Baker’s work will: reduce westbound SR-91 mainline congestion; improve local mobility and safety; modernize freeway, local and system interchange operations; and minimize adjacent right-of way, environmental and economic impacts.
Additional efforts include:
  • -Refining geometrics for the system and local interchanges to measurably improve traffic operations with both the freeway and the arterial street networks;
  • -Identifying logical starting and ending points for the westbound SR-91 widening that address operational concerns;
  • -Incorporating community and agency input into the project approval process;
  • -Delivering a project that is within the available programmed funding and is environmentally cleared to move to the final-design phase within 36 months or less. 
“Michael Baker’s thorough understanding of the project lets us advance at full speed,” said Steve Huff, Michael Baker International, Transportation Practice Lead, Southern California. “In this way, our unique knowledge of the dynamic interplay between the transportation improvements we’ve identified will aid us in solving their challenges and help ensure that “We Make a Difference” for the community and region by making their residents’ commutes less stressful and their freeways less congested and safer.”