The number of pedestrians killed in U.S. traffic accidents are rising faster than ever before.

One study suggests that number spiked 10 percent, in 2015 alone. Michigan traffic safety experts have spent years working on this growing problem.

Since 2013, the number of pedestrian accidents in Michigan has grown each year. That is according to the Michigan Office of Highway Safety Planning. Historically, October has been a very bad month when it comes to car versus pedestrian accidents.

In West Michigan there have been four pedestrian accidents in the past three days. Two of those accidents were fatal.

Pedestrians now represent the largest portion of U.S. traffic fatalities, in the past 25 years. Traffic safety officials started tracking these numbers about 40 years ago. They predict we could be looking at the largest year-to-year spike since then.

Last year, in Michigan, there were more than 2,400 people hit by cars -- 170 of those people died. In most cases either the driver or pedestrian was under the influence or distracted.

Most pedestrian accidents occur between 5 p.m. and 7 p.m. Most pedestrian deaths occur between 6 p.m and midnight. Many occur when people cross somewhere other than at an intersection.

To minimize risk, experts advise pedestrians to cross at traffic lights and crosswalks, make eye contact with drivers before crossing the street -- and if there's no sidewalk, walk on the left side of the road, facing traffic.