A Detour de Force : Riverside-Costa Mesa Interchange Work to Shift Autos to 3 Lanes

Traffic is about to move on the Riverside Freeway.

Well, sort of.

With work crews rebuilding the junction of the Riverside and Costa Mesa freeways--part of a $125-million, 10-mile project to install the nation’s first private toll lanes--all eastbound traffic will be moved to three newly paved detour lanes next to Santa Ana Canyon Road here, officials said Tuesday as they unveiled plans for the interchange.

The reconstruction of the interchange will include some unusual features, such as a reusable steel bridge that will cost the contractor an extra $2 million.

“We’re using some of the most innovative techniques available for highway construction today, and the public will benefit,” Construction Manager Dennis Davis said.

But first comes the shift of traffic, scheduled to begin in three weeks. It will allow construction crews enough space to double the number of lanes on the southbound Costa Mesa Freeway from two to four, with direct connections between the Riverside Freeway toll lanes and the Costa Mesa Freeway’s car-pool lanes.

The two-lane tunnel at this location is now one of the county’s worst bottlenecks, sometimes backing up traffic for miles.

But the detour is just for starters at this heavily congested interchange, which handles more than 250,000 vehicles per day. Traffic volume is expected to reach 320,000 to 400,000 vehicles per day by the year 2010.

Next month, work starts on a $2-million, recyclable steel bridge that will temporarily carry eastbound Riverside Freeway traffic over the southbound Costa Mesa Freeway.

During a media tour of the site Tuesday, officials touted the bridge as an innovative attempt to shave construction time at the interchange from 42 to 29 months. Use of the bridge will enable crews to work in both traffic directions at once, instead of the traditional one side of the freeway at a time.

But the first thing motorists are likely to notice while driving past the project in the next two weeks is the paving of the new toll lanes--two in each direction--in the dirt median between Lakeview Avenue and Imperial Highway. Eventually, they will extend 10 miles from the Riverside County line to the Costa Mesa Freeway.

The downside: It will be December, 1995, before the toll lanes open to traffic, because the reconstructed freeway interchange won’t be ready until then.

But when the lanes do open, motorists will pay tolls ranging up to about $2 or $2.25 depending on traffic conditions--the nation’s first test of variable pricing designed to collect the most money from motorists who travel during rush hour.

And these will be the first totally electronic toll lanes. California Private Transportation Co., the firm that will build and operate the lanes, will distribute to motorists thick credit cards embedded with tiny transmitters. An antenna mounted above the roadway will transmit signals that activate the high-tech cards, which transmit motorists’ account codes back to the toll system’s computers. Tolls will then be deducted from prepaid accounts.

The project, which began construction July 27 under special legislation adopted in Sacramento four years ago, is being watched closely by experts worldwide as a model for privately financed and operated toll roads.

Under terms of the legislation, California Private Transportation Co., whose major partner is Omaha-based Peter Kiewit Sons’ Inc., the toll lanes will revert to state ownership after 35 years.

During Tuesday’s media tour at the interchange, Davis, the construction manager, said engineers were faced with a daunting task: “We have to keep traffic flowing in the same number of lanes that exist right now, while rebuilding several major freeway structures,” he said.

The temporary bridge is unique, Davis said, because Caltrans would never have spent the extra money, even though it cuts nearly a year off the project’s construction schedule.

As part of the toll-lane project, workers from Granite Construction Co., the general contractor, will fill gaps of air that currently exist between the eastbound and westbound lanes at four freeway over-crossings in order to place the toll lanes in the middle.

And sound walls requested by local residents for years are finally being erected.

Davis said all freeway lanes will remain open during the day, with closures limited almost entirely to nighttime hours.

“We don’t expect any traffic delays due to construction, because we’re keeping the same number of lanes open that were already there, and we’ll have gawk boards up to prevent motorists from slowing down to watch what’s going on,” Davis said.

Sometime next May or June, he said, the westbound Riverside Freeway lanes will close, but traffic will be diverted to new, permanent lanes being built north of the existing freeway--close to some of the homes now getting a sound wall.

Once all traffic is moved to new lanes, construction will proceed on a new ramp in the middle of the interchange. The ramp will provide direct connections between the Riverside Freeway toll lanes and new car-pool lanes being built by Caltrans and the Orange County Transportation Authority on the same freeway farther west.

Reconstructing an Interchange

The first detours for the heavily congested Costa Mesa Freeway / Riverside Freeway interchange open next month as part of a privately financed $125-million tollway project to be completed by 1995.

1. Eastbound 91 / Northbound 55: Detour opens November; traffic rerouted on three new lanes.

2. Eastbound 91: Construction begins November on temporary steel bridge over 55 freeway. Concrete bridge will be demolished.

3. Westbound 91: Construction starts spring 1994; traffic moves three lanes north of current lanes.

4. Southbound 55: Construction starts mid-1994; two lanes expand to four with direct connection from toll lanes on 91 to car-pool lanes on 55. Source: California Private Transportation Co; Researched by JEFFREY A. PERLMAN / Los Angeles Times.