Overlay increases safety on INDOT highways

By: Tom Donnelly

Extending almost 884 miles from Mobile, Ala., to Gary, Ind., I-65 is one of the busiest north-south transportation corridors in the central U.S. About 45 miles north of Louisville, Ky., I-65 traverses a low-lying wooded landscape where it crosses several tributaries of the Muscatatuck River. Three crossings are located within a quarter mile of each other near mile marker 45 and have a history of icing up during the early morning hours of winter.

Most notably, the Vernon Fork Bridge, which is shaded by nearby trees, has seen its share of truck jackknifes. To remedy the situation, the Indiana Department of Transportation’s (INDOT) Seymour District chose to install SafeLane anti-icing surface overlay on the northbound lanes of the Vernon Fork Bridge. The district made that decision based upon three years of success with the overlay in the LaPorte District, near South Bend.

Approximately 35,000 vehicles cross the 500-ft-long Vernon Fork Bridge each day, with almost 30% of that volume being truck traffic. To save time and money, Seymour District chose to install the anti-icing surface overlay with its own maintenance staff. The district expedited the installation by using an automated chip spreader, completing the project in two days while maintaining an open lane for traffic.

After the first winter of plowing and significant daily commercial traffic, the overlay continues to provide all-weather friction. Recent measurements report friction numbers ranging from 56 to 64.

Eliminating accidents on I-64

Traversing almost 954 miles from its beginning in Chesapeake, Va., to its terminus in St. Louis, I-64 provides a vital transportation link in Indiana, connecting Louisville, Ky., on the east to Evansville, Ind., on the west. But it is near Evansville where the INDOT Vincennes District needed a solution to a problem section of pavement that was prone to hydroplaning.

In fall 2007, Vincennes District maintenance crews installed 2,000 ft of SafeLane anti-icing surface overlay in the passing lane near mile marker 27. The eight-man crew installed the overlay in less than a day by using the district’s automated chip spreader. One lane of traffic was maintained during construction. This portion of I-64, near its junction with U.S. 41, experiences about 20,000 vehicles per day, with almost 30% of that volume being truck traffic. Vincennes District engineers decided to try the overlay based upon the results it had seen in another district.

Since its placement on I-64, there have been no reported accidents resulting from hydroplaning nor have there been any winter-related crashes.