Speed and alcohol appear to be factors in a motorcycle crash in Wahiawa that critically injured a Wahiawa man Sunday afternoon, police said. 

The crash happened in the town-bound lanes of Kamehameha Highway near Ohai Street at about 2:30 p.m.

Police said a 47-year-old Wahiawa man was speeding when he lost control of his 2010 Harley Davidson motorcycle and hit the rear of a 2001 Toyota Tacoma truck driven by a 50-year-old

The motorcyclist suffered critical head and internal injuries, police said. He was not wearing a helmet. 

Police closed two south-bound lanes of Kamehameha Highway from Ohai Street shortly after the crash. The lanes remained closed until just after 6 p.m.