Adding a northbound carpool lane may be the most known part of the I-405 Sepulveda Pass Improvements Project. But the project will also rebuild the Wilshire Boulevard ramps to and from the 405 to eliminate a conflict on both sides of the freeway in which traffic trying to enter the freeway gets tangled with vehicles trying to exit to Wilshire.

Here are an overview of the ramp work on the project home page and two renderings show what the project aims to do. There is also a good story on ZevWeb, the website for County Supervisor and Metro Board Member Zev Yaroslavsky.

Click above for a larger rendering of the new Wilshire ramps to be built.

Advance Notice Motorist Travel Advisory
90-Day Closure of Two I-405 Freeway Ramps at Wilshire Boulevard Planned Beginning June 22, 2012

Los Angeles, Calif. – Plan Ahead, Adjust Travel Times, or Share the Ride. That’s the new message public officials are advising motorists in the greater West Los Angeles region to help reduce severe congestion resulting from the first extended, 90-day closures of key Wilshire on- and off-ramps to the I-405 now scheduled to officially begin Friday, June 22, 2012.

The Los Angeles County Metropolitan Transportation Authority (Metro), Caltrans and Los Angeles Department of Transportation are giving the public advance notice that the I-405 Sepulveda Pass Improvements Project contractor must begin demolishing and reconstructing eight heavily traveled freeway ramps at Wilshire Boulevard in order to complete the construction project schedule. This single interchange is where one of the nation’s busiest boulevards meets the nation’s busiest freeway, where tens of thousands of freeway-bound motorists travel on a daily basis.

Demolition and reconstruction of the Wilshire ramps is required to build a 10-mile carpool lane on the northbound I-405 between the I-10 and U.S. 101.

Ninety-day closures for the first two Wilshire Boulevard ramps are as follows:

•Westbound Wilshire on-ramp to the Northbound I-405. Detour: Motorists should travel northbound on Sepulveda Boulevard to access the Moraga on-ramp or travel southbound on Sepulveda to access the Santa Monica Boulevard on-ramp.

•Northbound I-405 off-ramp to Westbound Wilshire. Detour: Motorists should exit freeway using Santa Monica off-ramp, then proceed northbound on Sepulveda to Wilshire Boulevard. Other alternatives include the off-ramp at Sunset Boulevard.

This fact sheet helps explain the improvements that will be made to the 405/Wilshire ramps.

Also as an alternative, vehicles traveling Northbound/Westbound on the I-405/I-10 will be directed to exit at Bundy Drive to reach their original westbound Wilshire destinations.

All recommended detours are on major city streets. Motorists should not use local residential streets to detour through the area, as these streets are intended for local access only.

The six other Wilshire ramps will be closed consecutively, some two at a time, between 14 and 90 days. A closure schedule for these remaining ramps will be announced at a later date.

Because of the importance of ramp reconstruction work to the ultimate completion of the project, the contractor will be working night and day. This schedule will enable the work to be performed and completed as quickly as possible and will shorten the duration of traffic impacts.

To help manage impacts for these closures, a network of changeable message signs will be used to facilitate detours and provide motorists with information that will give drivers the opportunity to choose an alternate route.

Initially, traffic control officers will be at key intersections to help keep traffic moving, particularly during peak travel periods. As traffic patterns develop, traffic officer deployments will be adjusted accordingly. The timing of traffic signals will be monitored closely by LADOT, which can make adjustments to manage traffic conditions.

Motorists who commute in the area are advised to plan ahead and select their detour routes in advance and monitor real-time traffic conditions at go511.com or local traffic news reports before beginning their trips. Drivers should avoid discretionary trips at the Wilshire/I-405 interchange, especially during the peak-hour commute periods.

Drivers who must drive in this area should adjust their travel times to compensate for the additional time that will be required to negotiate Wilshire Boulevard, Sepulveda Boulevard and connecting arterials for this extended period. Workers are encouraged to determine if their employers will allow them to change work hours or work shifts to avoid peak hour congestion. Employers may also be able to offer telecommuting options for one or more days per week.

L.A. drivers are also urged to share the ride, if possible, to reduce the number of vehicles traveling in the West Los Angeles area and points north and south. Numerous public transportation options are available, and can be discovered using the Metro Trip Planner on metro.net.

Major east/west bus services serving Wilshire Boulevard include Metro Rapid 720, Metro Local 20, Santa Monica Big Blue Bus 1 and 8. LADOT Commuter Express Lines 431 and 534, 573 can also connect commuters from disparate geographical areas using freeway lanes. FlyAway buses to and from LAX are also available in Westwood, Van Nuys, and Downtown Los Angeles, among others. Santa Clarita Transit Line 797/792 and the Antelope Valley Line 786 also serve the area.

Commuters may elect to join a company vanpool or start or join a carpool and save time by gaining access to available freeway carpool lanes. RideMatch.info provides one-stop ridematching services to Southern California commuters. Alternately, commuters can also call 323.GO.METRO (323.466.3876) Option 3, for assistance in setting up a ridesharing relationship.

Once built, the reconstructed Wilshire Ramp interchanges will produce some of the I-405 project’s greatest local traffic improvements. By building new, seismically updated and higher capacity ramps, the project will reduce the vehicular conflicts between Wilshire Boulevard and the I-405. This should reduce backup at other north/south streets, and bring capacity to meet expected vehicle demands in 2031.

Motorist safety will also be improved with the new interchange. The existing off-ramp/on-ramp configuration presents a dangerous weave situation at two regionally important intersections: the Westbound Wilshire Boulevard on-ramp to the southbound I-405, and the Southbound I-405 off-ramp to eastbound Wilshire Boulevard. At both these locations, drivers struggle to reach a through-freeway lane or change lanes to reach the of
f-ramp exit within a very short distance. New flyover ramps at these locations will be built to physically separate vehicles and eliminate these conflicts.

After reconstruction of ramps, to improve safety for pedestrians and bicyclists, zebra striping will be added to the bottom of the rebuilt ramps as well as flashing caution lights.

The $1 billion freeway improvements project is a joint effort between Metro and Caltrans, and is being constructed by Kiewit Infrastructure West Co. It is scheduled for completion in 2013.

For latest updates visit the project web site at www.metro.net/405 or follow the project on twitter: twitter.com/I_405 and Facebook at facebook.com/405project.