Date: April 1, 2014

Whitetopping Case Study of Interchange I-595 & US301

Heavy traffic at the interchange of I-595 & US301 (also routes 50 and 3) in Bowie, MD had caused significant damage to the asphalt roadway.  More than 100,000 vehicles use the interchange daily and many of those are large heavy vehicles. The damaged roadway was causing a safety hazard for drivers, as they entered or exited the ramps, uneven pavement and serious rutting caused drivers to struggle with keeping their vehicles safely on the ramps.

The Maryland State Highway Administration (SHA) identified this as a perfect place to use a bonded concrete overlay called whitetopping.

Whitetopping is a concrete overlay that covers damaged asphalt and is a long-term solution that actually grows stronger over time. whitetopping typically lasts twice as long as other resurfacing methods, reduces rutting caused by larger vehicles and its durability produces savings through less frequent road repairs, lane closures and construction zones.

Concrete reflects light making the pavement brighter and reducing the need for lighting by up to 30%. Concrete is more rigid than asphalt which makes concrete roads 4% more fuel efficient for cars and up to 7% for large trucks. whitetopping is competitive on initial costs and has vastly superior life-cycle costs.

For this project, the existing flexible asphalt (HMA) was milled and replaced with 6” bonded concrete overlay with a curing compound and contraction joints. Nearly 20,000 square yards of concrete was placed, finished with a truss screed and diamond ground to provide a smooth finished roadway. This interchange will typically not need sealing or any other maintenance for the next 30 years. All work was done over a few weekends to minimize traffic disruptions.



Whitetopping Case Study of Interchange I-595 & US301



Whitetopping Case Study of Interchange I-595 & US301



Whitetopping Case Study of Interchange I-595 & US301