Partial cloverleaf interchanges, with on and off ramps next to each other, are the highway intersection most susceptible to drivers mistakenly entering on exit ramps, experts say. At such interchanges, “it’s hard to know which is the correct ramp,” said Andrea Bill, a traffic safety research project manager at UW-Madison’s Traffic Operations and Safety Laboratory. “Here in Wisconsin, especially in our urban areas, we have a fair amount of them.”
University Communications