Honolulu police are investigating whether speed and drugs were involved in a critical mo-ped crash Saturday on Ala Moana Boulevard near Piikoi Street.

Police are also investigating whether the mo-ped, driven by a 23-year-old Honolulu man, was weaving in–and-around cars before the 5:35 p.m. crash.

The mo-ped sideswiped a taxi, a 2004 grey Chevy Astro van traveling in the far left lane, and the driver was ejected from the mo-ped, police said.

Paramedics took the mo-ped driver in critical condition to the Queen’s Medical Center. He was not wearing a helmet.

The 56-year-old Honolulu man driving the taxi and four passengers, tourists from Michigan, were not injured.