MADISON, Wis. -- The number of motorists killed in traffic crashes last month was the second lowest since World War II, but motorcycle fatalities climbed significantly, according to state officials.

State transportation officials said motorcycle deaths jumped to 28 at the end of May, compared to 15 fatalities at the same time last year.

DOT safety chief Dennis Hughes urges motorists to be on the lookout for motorcyclists as the improving weather increases their activity.

Forty-eight people were killed on state roads in May, the second lowest since World War II. The lowest number of traffic deaths in May was set last year at 47.

Last year, 589 people died on Wisconsin roads, the lowest total since 1944.