The history of UFO, extraterrestrial sightings, and encounters include numerous accounts of people in cars seeing  aliens crossing the road.  In many cases the people come close to causing deadly accidents.  On rare occasions aliens have caused deadly disasters.

MUFON, North American's largest UFO investigation operation, recently received this eyewitness account that happened in Florida in 1985:

"We had gone to Miami for a meeting and took our children. On the way home, I was driving into the night and everyone in the car was asleep. We were coming to a overpass-and I saw something in the road and I kept trying to figure out what it was and I was driving about 70 miles per hour and I started slowing down because I could not see what it was-then all of a sudden I slammed on the brakes because I saw 4 alien beings- they were moving in a straight line from one side of the highway going to the other side. (There was 2 tall ones and 2 much shorter ones) It looked like they had on a one piece skin tight outfit that even went over their heads. When I slammed on my brakes they all turned their heads toward the car and vanished. They all had oval heads with large eyes. I saw something out of the corner of my eye on the other side of the road and it was gone. Maybe like a flash. My family picked themselves up off the floor and asked what was going on and I told them. They made fun of me and I had tried to dismiss it, but I know what I saw."

Alien sightings on roads have also occurred in China.

In the city of Xuanwei, a 28 year old man was killed in an accident that involved no witnesses or other drivers.  Shortly after the accident, very unusual footprints were found leaving the scene of the accident.  Rumors were spread over the internet that the driver, who died shortly after arriving at the hospital, told medics that he saw a stange creature or alien crossing the road.

The story spread like wildfire and people were visiting the crass site to look at the alien footprints.  Oddly the footprints were imprinted on hard cement.  Some have said that the footprints might be that of a dog and others have said that they are completely irregular.