New research from the Carnegie Mellon University’s College of Engineering, in partnership with the Pennsylvania Department of Transportation (PennDOT), found that work zones more than 1.8 miles long could increase crash risks; and that road work scheduled for night hours do not increase crash risks.

“So far, we cannot say what mitigation efforts can lead to the safest work zones; this will be our next step. But this provides insights on under what conditions a work zone can lead to more crashes, and when a work zone does not,” said Sean Qian, professor of civil and environmental engineering and director of the Mobility Data Analytics Center…

If lengthy work zones on heavily traveled roads have shown increased accident risk during day hours, transportation officials may want to consider steps to make these work zones safer as a result, say researchers.