The Washington State Department of Transportation is returning to Pullman to improve the curb ramps installed along Highway 270 this summer, after the department found that the ramps were tripping hazards for walkers.

The work on the highway, at the entrance to Pullman, began yesterday and will continue until next Monday.

“There will not be any lane closures, but just a few restrictions,” said Al Gilson, a communications manager for WSDOT’s Eastern Region.

The highway was part of a $2.3-million paving project in late July, which included rebuilding 67 intersections and sidewalk curb ramps to comply with the current Americans with Disabilities Act standards.

Gilson said WSDOT had problems installing the ramps, which are required to slope at 10 percent or have shallow wing slopes, because of their proximity to utility access panels and poles.

Although the ramps meet the ADA standards, the vertical faces they installed as an alternative were later determined to be unintentional trip hazards for pedestrians at a few locations.

WSDOT is now modifying 13 of the curb ramps to eliminate the vertical faces. Gilson said the cost of the modification will be about $65,000.

The streets under construction include Davis Way, Grand Avenue, Main Street, and Paradise Street.