Los Angeles County Public Works (PW) has utilized sustainable pavement treatments with remarkable success since 2008. We continue our commitment to preserving and improving the quality of our roads in a cost effective and environmentally responsible way. The state mandate (AB32) to reduce greenhouse gas (GHG) emissions and limited budgets were key motivators for developing our sustainable approach that emphasized (1) focusing on preserving roads in good condition first; (2) using recycled materials in pavement treatments; and (3) reutilizing materials in-place when reconstructing our roads. The Avenue E project, completed in October 2019, showcases the benefits when properly applying this approach. The project covers 9.5 miles (1.2 million feet²) of a major highway with heavy truck traffic in the unincorporated community of Roosevelt. The pavement had a poor condition rating and exhibited widespread distresses and localized base failure. Rehabilitation was considered as the best solution. Traditional rehabilitation method of removing and replacing the existing asphalt materials was estimated to cost $2.9 million. The County’s proposed sustainable rehabilitation approach method of reutilizing the in-place materials was estimated to save $720,000 and achieved significant environmental benefits. The project scope included recycling 3” of the existing asphalt concrete (AC) using the Cold In-Place Recycling (CIR) process and constructing 1½” of Asphalt Rubber Hot Mix (ARHM) on the CIR AC. The streamlined approach of recycling the AC in one pass using CIR process enabled the paving operations to be less impactful to the community, reduced construction workdays, and mitigated traffic impacts. Environmental benefits included a reduction in GHG emissions by 79%, in energy usage by 77%, and landfill by 9,400 yards³. The ARHM resulted in 8,500 scrap tires being diverted from a landfill. The cost savings of $720,000 was reinvested to improve other County roads. The project was delivered utilizing Job Order Contracting (JOC) along with support from own forces to perform the pavement preparation work and shoulder grading. The JOC process is a flexible unit price contracting method used to complete maintenance, repair, and refurbishment of County roadway infrastructure and building facilities. This was the first time PW us JOC for this type of road rehabilitation in an effort to explore innovative ways to deliver projects more efficiently. The Avenue E project improved the overall quality of the County’s road network in a cost effective and environmentally friendly way. The County’s sustainable approach is a straightforward formula for addressing the issues of limited funding and reducing GHG in a practical manner, while providing direct benefits to our constituents. The use of JOC also allowed the project to be delivered in an accelerated yet efficient manner. PW welcomes opportunities to share our experiences and collaborate with other local agencies.
35th Street East to 130th Street East
City or County Responsible for Project:
Los Angeles County
Roads: Efficient and Sustainable Road Maintenance, Construction and Reconstruction Projects.
Narrative Description Of Your Entry:
Assistant Deputy Director
Los Angeles County Public Works
900 South Fremont Avenue, Alhambra, CA 91803