A sharp curve on Pennsylvania's Route 611 had a persistent safety problem that conventional road signs and markings could not solve. When rain covered the pavement, drivers faced a combination of low surface friction and difficult road geometry, increasing the risk of skidding and leaving the roadway. In 2007, the Pennsylvania Department of Transportation tried a more targeted solution: applying a high-friction surface treatment to about 800 feet of the curve.
The Federal Highway Administration recorded no wet-pavement crashes at the treated location for the eight years following installation, a dramatic change from its earlier crash history. The result became an important early example of how improving tire-to-road grip at a specific trouble spot could deliver safety benefits without requiring the reconstruction of an entire roadway.
This stretch of highway was located in Northampton County on State Route 611, about five miles south of Easton, in an area known as Groundhog Locks. On the southbound side, the highway included a sharp horizontal curve on a two-lane rural road featuring narrow nine-foot travel lanes and no shoulders, making the site especially difficult to navigate. The curve was inadequately superelevated and contained an intersection within the curve itself, while right-of-way issues made widening or reconstructing the road impossible for PennDOT.
Federal evaluations reported multiple wet-pavement crashes over preceding ten-year windows, highlighting a recurring hazard. PennDOT had previously attempted conventional measures including warning signs, chevrons, and improved pavement markings, but these failed to address the underlying friction problem. Because curves require more lateral friction than straight sections to help vehicles resist sideways cornering forces, wet weather makes skidding and hydroplaning significantly more likely.
The high-friction treatment was applied to roughly 800 feet of the southbound curve in June 2007 as a pilot project, utilizing calcined bauxite aggregate and epoxy resin. Unlike regular aggregates that can become polished by traffic, calcined bauxite retains its skid resistance. The average skid number at the location jumped from 24 prior to the application to around 75 afterward.
Following the successful pilot, PennDOT treated 14 other high-incident spots in 2012 with assistance from federal initiatives. By the end of 2015, the agency had expanded the safety measure to 150 sites. Later internal evaluations confirmed significant statewide reductions in wet-road, roadway-departure, fixed-object, and total crashes, establishing pavement modification as a highly effective alternative to road reconstruction.