Kirker Pass Road Northbound Truck Climbing Lane

Location

Kirker Pass Road

City or County Responsible for Project

Contra Costa County

Category

Safety or Intelligent Transportation System Projects

Author

Jenna Caldwell

Organization

Contra Costa County Public Works Department

Address

255 Glacier Drive, Martinez 94553

Phone

(925) 500-3048

Project Description

Kirker Pass Road is an interregional route between Central and East Contra Costa County that serves as an essential route for approximately 20,000 vehicles a day, including 1,200 trucks. Due to the mountainous terrain with sustained grades greater than 10%, in conjunction with the high passenger vehicle and truck traffic, significant traffic congestion occurred during peak hours. The Kirker Pass Road Northbound Truck Climbing Lane project dramatically increases safety and reduces congestion along Kirker Pass Road by constructing a truck climbing lane in the northbound direction. To better serve the users of this road, this truck lane provides a dedicated lane for the slower, heavier truck traffic to climb the sustained grade, reduces frustration for commuters looking to make it to their destinations in a timely manner, and gives all drivers a better opportunity to make safer decisions. This project has six funding sources, including RMRA funds, and a construction cost of over $14 million. As part of the construction of the truck climbing lane, this project made significant improvements to the overall drainage systems and pavement condition within the project area. New slot drains were installed and the existing stormdrain system was expanded to collect and convey roadway runoff to two newly installed bioretention areas. These areas are designed to allow for gradual infiltration and to treat runoff from over 100,000 sqft of new and existing pavement. In addition to the added truck climbing lane, another improvement made by this project was the resurfacing of Kirker Pass Road with open graded rubberized hot mix asphalt (RHMA). To perform the required pre-pave grinding, equipment that utilized smaller teeth to produce a smoother ground surface was used. Not only did this improve the roadway condition for the public during the short duration between grinding and paving efforts, but this finer grind may have also benefited the smooth quality of the finished overlay. Open graded RHMA was chosen for this 2-mile stretch primarily because of its increased skid-resistance on the sustained uphill and downhill drive and ability to wick water from the pavement surface, but also because it reuses scrap tires, reduces noise pollution and requires less maintenance. This wearing course is a cost effective way to extend the lifespan of the pavement, especially on a road that experiences frequent and heavy traffic on a steep grade. This project required extensive coordination among many divisions within the Contra Costa County Public Works Department, as well as coordinating with the City of Concord, various utilities, private property owners, and working partners such as Mark Thomas Company, Parikh, Park Engineering, and Granite Rock Company. Thanks to this collaboration, the project was complete as of January 2021, and serves as an example of safe and efficient roadway design and construction for mixed-use traffic.