Los Angeles County’s Pavement Preservation Program

The Los Angeles County Department of Public Works (DPW) is committed to preserving and improving the overall quality of local streets and roads in a fiscally effective and environmentally responsible manner by utilizing our three-pronged sustainable approach. This approach incorporates the principles of (1) taking care of roads that are in good condition first; (2) using recycled materials in treatment selections; and (3) reusing existing materials in-place. During the months of October and November of 2016, DPW successfully delivered four pavement preservation projects that incorporated our three-pronged approach. These projects are Red Coach Ln, Casa Del Rey, Bellbrook St, and Eric St et. al. and were located within unincorporated Los Angeles County. The scope of work included preserving approximately 13.7 lane-miles of residential roadway equivalent to 2.2 million square feet of asphalt pavement mostly rated as fair to poor condition. The goal was to extend the service life of the pavement to avoid the much higher cost of reconstruct in the near future. The pavement preservation treatments utilized for these projects were a cape seal and slurry seal. The cape seal consisted of applying a slurry seal over a scrub seal. As DPW is committed to sustainability, all seal techniques utilized Reclaimed Asphalt Pavement (RAP) rather than virgin aggregate. In addition, to help improve the ride quality of the road, the contractor milled a thin layer of the roads surface (up to 3/8”) prior to applying the treatment. This process called micro-milling was used to smooth out irregularities of the road’s surface and to remove any excess material build up on the gutters. In-house forces were used to address curb ramp and parkway improvements for ADA compliance. Job Order Contract (JOC) was used to perform the pavement preservation work. The pavement preservation contract cost was $1.76 million ($0.81/SF) and is expected to extend the pavement service life for 8 to 10 years. When compared with equivalent life cycles of a conventional hot mix reconstruction alternative, performing preservation treatments save an equivalent of $1.5 million, reduces the energy consumption by 82%, and reduces greenhouse gas (GHG) emissions by 86%. In addition, using RAP instead of virgin aggregate not only prevented tons of old asphalt pavement from going to a landfill, it also saved tons of new resources from being removed from the earth. In summary, the projects directly preserved and improved the overall quality of the local streets and road system in a manner that is cost effective and environmentally friendly. The use of JOC expedited project delivery thereby positively affecting more communities compared to the low bid contracting approach. The County’s three-pronged approach is a commitment to implement sustainable projects, address existing funding shortfalls, and meet the objectives of the CA Global Warming Solutions Act of 2006 (AB 32) of reducing GHG emissions.