Three, two, one ...

After years of planning, leveraging local resources, and construction, we are in the final days of our countdown to the opening of the fourth bore of the Caldecott Tunnel. Barring last-minute changes between this writing and publishing this column, the tunnel will open to traffic next week!

Through close collaborative management by Caltrans and our Contra Costa Transportation Authority, the tunnel will be open ahead of schedule and within the original budget, both significant achievements.

Highway 24 currently carries about 160,000 vehicles daily through the three existing tunnels. Traffic congestion is experienced in the peak and off-peak directions. The new fourth bore will relieve congestion in the noncommute direction by permanently dedicating two bores to westbound traffic and two to eastbound traffic.

Matching the number of tunnel lanes to those on the highway to the east and west of the tunnel eliminates the need to reverse traffic direction in the center bore twice a day to accommodate morning and evening commute traffic, and adds greater predictability to travel times on weekends.

The new tunnel has sophisticated fire-life-safety systems and intelligent technology. Tunnel systems will help with traffic management.

The VID cameras will monitor traffic patterns and alert an operator if there is a slowdown or accident. There are linear heat, carbon monoxide and nitrous oxide detectors to monitor fire and air quality.


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Both Oakland and Moraga-Orinda fire departments will respond to tunnel fires. To shut down the tunnel, stop lights outside the tunnel entrances will be turned on. Seven cross-passages along the tunnel will allow access between bores three and four for evacuation. Both bores will be shut down in an emergency to allow safe evacuation from either bore to the other.

The cross-passages have closed-circuit televisions and intercoms so operators can monitor and communicate with anyone inside. The passages also have a ventilation system that will provide positive pressure inside, preventing smoke and flames from entering.

There are 17 emergency stations equipped with fire extinguishers, manual fire alarms and emergency phones. In the event of a fire, 19 bidirectional jet fans will be activated along with the ventilation system and can redirect air flow.

Even the tunnel lining has been built with special fibers that shield the tunnel from heat to prevent a strong fire from damaging the tunnel structurally.

Variable message signs at the portal and within the tunnel will display preprogrammed messages triggered automatically when there is an event. A tunnel radio system will be able to override other radio stations to give emergency information to motorists.

A state-of-the-art Operations and Maintenance Control (OMC) building is under construction. The new facility will be the "nerve center" for the four Caldecott tunnels, as well as the Webster-Posey tubes in Alameda County.

The OMC will be staffed 24 hours a day and seven days a week by specially trained operators, who must pass a rigorous test administered by the state fire marshal before the tunnel opens to traffic.

In addition to these systems, the tunnel will also feature strong monitors to detect seismic activity. The information gathered will be sent to the California Geological Survey to help predict future earthquakes. The new tunnel is designated as a regional lifeline structure and is designed to reopen to emergency traffic within 72 hours of a major earthquake.

The necessary planning, environmental clearance and construction of the fourth bore of the Caldecott Tunnel has been a major project on our countywide self-help sales tax expenditure plan for more than 20 years. Our voter-approved Contra Costa sales tax dollars contributed $124.6 million to the $417 million total cost of the new tunnel.

Our local funds were leveraged more than three-to-one by state and largely federal funds. In the absence of state bond capacity during the recession, federal American Reinvestment and Recovery Act (ARRA) funds provided $194 million, making the tunnel one of the largest Recovery Act projects in the country.

Regional toll bridge and state funds also contributed. The fourth bore provided thousands of jobs to stimulate our county's economy during the recession while completing this marquee project.

Echoing the Art Deco style of the 1937 Caldecott tunnels, the portals each feature three decorative medallions designed by local Contra Costa and Alameda county students. I know we are all looking forward to our improved commutes and will enjoy driving through our new tunnel.

Pierce is the mayor of Clayton. Email her at transcript@bayareanewsgroup.com.