February 8th, 2012
GET A GRIPUncategorized, by Catherine Higgins.
UDOT will test a how high friction surface treatments increase skid resistance and improve safety.
Pavement-tire friction provides skid resistance and helps motorists break safely. Departments of transportation evaluate pavement friction by objectively scoring skid resistance – a score of 40 or more usually represents adequate friction while “35 or below is a trigger value,” says Barry Sharp. He and others at UDOT and the Federal Highways Administration are working on a project to improve the skid resistance at key locations by applying a high friction surface treatment – HFST – consisting of an epoxy binder and non-polishing aggregate.
FHWA is reaching out to UDOT and other states to promote the study and possible implementation of market ready products including HFSTs. Other states have used HFSTs and realized an immediate reduction in crashes. In Utah, using an HFST “could be huge in terms of saving lives,” says John Haynes, Research and Innovation Manager at FHWA.
Steep roadways, freeway ramps or sharp curves may benefit from a highly skid resistant surface. UDOT engineers work to keep roads as safe as possible by maintaining skid-resistance and setting appropriate speed limits. But, rain and speeds that are too high can combine to make for dangerous conditions, especially for semis or other very large vehicles.
UDOT Engineers will identify some locations that could benefit from HFST by checking crash data for run-off-the-road collisions. Before and after studies, including IRI measurements and crash data, will provide the basis of an evaluation, explains engineer Abdul Wakil, UDOT Research Project Manager. Engineers will also look at how the product holds up under traffic, weather and snow plows.
Brent Gaschler, UDOT Engineer for Technology and Support has taken a preliminary look at how improving skid-resistance is expected to help reduce crashes. “it’s a really wise investment even though it seems to have some up-front costs; we expect the long term benefits to outweigh initial expenditures.” Several HFST products are available, but the product UDOT will use for the study will be determined through a competitive bidding process.
“If this treatment is successful, we may draft a specification or special provision for UDOT,” says Wakil. Adding a UDOT Specification will make it easier for UDOT Project Managers to add HFST to projects, and for contractors to select an appropriate product.