Ada County Highway District

2010 Local Overlay Projects

General Description:

Each year the condition of roads throughout Ada County is closely assessed and a priority system is used to determine which roads have the greatest need for re-surfacing. The 2010 overlay road projects will resurface and improve more than 40 road segments, making this a very busy construction season on Ada County roads.

Two types of overlays will be done this summer:

  • A "full depth" overlay involves grinding down the old roadway surface approximately two inches from curb to curb and placing new asphalt on the freshly ground surfaces.  All pedestrian ramps adjacent to each full depth overlay are upgraded to current Americans with Disabilities Act (ADA) specifications.
  • A "thin lift" overlay is less extensive, requiring only the milling of existing road surface next to areas with curb and gutter. Thin lift overlay locations receive a slightly thinner layer of asphalt, as its name implies. Overlay projects are an important component to roadway maintenance. Smooth roads have a longer life because they create a better driving surface, allowing traffic to have less impact on the roadway.  The process also replaces weathered and worn materials and reseals the roadbed to prevent moisture from causing major structural damage. Smooth roads also make the driving experience safer and more pleasant for motorists.

Construction Impacts & Work Hours

Overlay work began in early May and will run through fall 2010. More specific time frames for work at each location can be found on the Overlay Locations page. Each overlay location will take approximately one week to complete, however, some locations may take more or less time. Because the overlay projects are funded through different sources, it is likely that multiple contractors will be performing the work. Each contractor will be allowed to perform traffic-hindering work on three locations simultaneously, however; it is likely that several locations throughout the county will receive overlays within the same time frame.

Many overlay locations are scheduled for night work to occur, typically from 7 p.m. to 5 a.m. Performing night work allows construction to occur faster and under safer conditions for residents, motorists and crews and reduces the need for lane restrictions or closures.

Overlay work is typically a quick process, but includes several steps, some of which can involve, but are not limited to:

  • General construction noise
  • Ground vibration
  • Equipment safety back up alarms
  • Dust
  • Night work lighting
  • Temporary lane restrictions & delays

During weekdays in business or commercial areas, the contractor will be allowed to perform night work from 7 p.m. to 5 a.m.; and in residential areas between 8:30 a.m. and 4 p.m. and again from 6 p.m. to 10 p.m. The contractor will be allowed to set his own schedule during weekends. These time limits are intended to help reduce impacts to traffic but also to diminish adverse impacts to residential neighborhoods. One travel lane in each direction will remain open to traffic at all hours of the day and may be controlled by flaggers.


Time Frame

Start Date:
May 2010
End Date:
Fall 2010

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