From its creation in 1975 to just a couple of years ago, the nearly 40-year-old Interstate 805 freeway has never undergone a substantial change.
While freeways surrounding it -- such as the Interstate 15 and 5 corridors -- have been changed in ways that promote carpooling, bus use and other transit opportunities, I-805 was left with its infrastructure based on an aging view of transportation in San Diego County.
In the meantime, the freeway has come to be known for the area's worst traffic bottlenecks.
"Overall, 805 is basically comparable to I-5," said Gustavo Dallarda, Caltrans' I-805 corridor director.
He said that's why major projects in the freeway's northern and southern halves are critical to preparing it for a future that calls for up to 100,000 additional vehicles on its lanes each day.
The $1.1 billion I-805 South Express Lanes project and the $600 million I-805 North Express Lanes project have different budgets and timelines but share a common goal: to expand transportation options for drivers in a corridor that desperately needs them, Caltrans officials said.
Each separated into phases that will span many years, the two projects are gradually transforming the freeway.
Phase 1 in the south, which so far has added a carpool lane in each direction from Palomar Street in Chula Vista north to state Route 94, has already proved its usefulness to Ramon Martinez, Caltrans' project manager for the southern I-805 corridor.
A resident of Eastlake, Martinez commutes to work via his project's route.
As a regular carpooler, he said, drive times have improved since the carpool lanes opened in March. It used to take close to an hour to get to work, Martinez said, but now it takes half that time.
Even non-carpool traffic appears eased somewhat, he said, as fewer vehicles battle for space in general-purpose lanes. But more than easing congestion, the combined projects' goal is to provide choice and flexibility.
Martinez called the projects the "backbone of a completely new transportation system” that will create alternatives on the 805 that never existed, such as interconnection with transit systems.
Still under construction is the southernmost portion of the new carpool lanes, from Naples Street to Palomar Street in Chula Vista, and the infrastructure to provide access to the separately planned South Bay Bus Rapid Transit system, or BRT.
The additional Phase 1 work, expected to be completed in spring 2015 by Granite Construction, includes a direct access ramp to the new express lanes from East Palomar Street, a new transit station at East Palomar, and lots in which transit riders and carpoolers can park their cars.
Granite was also the contractor behind the express lanes that opened in March. Phase 1 also included the construction of 10 sound walls, completed in June by Western Rim Constructors.
The second phase of the I-805 South Express Lanes Project, though not fully funded yet, plans to expand the new carpool lanes into Express Lanes, allowing solo drivers using FasTrak to access them.
In-line transit stations are also planned for Phase 2 as well, to be built in the freeway median at East H Street in Chula Vista and Plaza Boulevard in National City.
Direct freeway-to-freeway carpool connectors are also planned for between I-805 and I-15, and an additional 80 sound walls are proposed.
The San Diego Association of Governments is Caltrans' planning partner.
SANDAG board Chairman Jack Dale has noted that the goal of planning for an intermodal transportation future relies less on adding lanes and more on making multiple uses from shared infrastructure.
“We are going to transform the I-805 into a multimodal corridor, making it more efficient," Dale said.
The direct access ramps, carpool and express lanes, and future BRT services will lead to faster, more frequent and more convenient transit service, officials said.
On the freeway's northern half, drivers haven't been able to use some recently completed carpool infrastructure yet. It's not for lack of wanting to use them, Caltrans officials said, but because of some complexities with the I-805 North Express Lanes project.
Phase 1 of the project -- awarded as an $86 million design-build contract to Skanska USA Civil West -- includes building one carpool lane in each direction from north of state Route 52 to north of Mira Mesa Boulevard.
It also includes building of a south-facing direct access ramp on the north end at Carroll Canyon Road and the widening of bridges, such as Rose Canyon and Governor Drive.
As of mid-August, the southern two-thirds of the required median widening for the new carpool lanes had been completed.
Ron Caraet, manager of the I-805 North Project, said he believes the new southbound carpool lane could be open soon from Route 52 to La Jolla Village Drive.
He said he's working to expedite that process, but opening the completed northbound lane won't be practical for a while because of continued work on the project's northern third.
The job is not without its other challenges, he added.
The widening of two bridges that allow the north and southbound lanes to cross over Carroll Canyon Road poses a particular environmental challenge and a need for careful design.
"That's work over an environmentally sensitive canyon, and those two tall bridges will be widened on the sides, on the right-hand side, about 50 feet each," Caraet said. "So that's all new columns to mirror the existing columns. And that bridge is over 100 feet up in the air at its highest point. That height alone is a challenge."
As part of mitigation for the I-805 North project, SANDAG and Caltrans are partnering to restore a 31.4-acre habitat site in Carmel Valley known as Deer Canyon.
The restoration aims to attract the endangered bird Least Bell’s Vireo to the site and keep the land preserved in perpetuity.
In the coming weeks, Caltrans hopes to finish the bridge widening there so it can shift traffic, which has been directed closer to the median, back toward the outside of the bridges.
That will allow Skanska to focus on building the direct access ramp in the median. As of mid-August, about half of the work in the design-build contract had been completed.
Though not expected to begin until at least 2017, phases two through four of the project will include a second carpool lane in the median from just north of Route 52 to La Jolla Village Drive.
Those stages will also bring a new direct access ramp at Nobel Drive, along with a Park and Ride transit station.
A fifth phase would include a direct freeway-to-freeway carpool connector in the median, from Route 52 to northbound I-805 and from southbound I-805 to eastbound Route 52. This stage isn't planned to begin until at least 2037.