A 34-year-old moped rider was critically injured after he crashed into a vehicle in Waimanalo Monday, Honolulu police said.

The rider was traveling westbound on Kalanianaole Highway on a Zhong moped and weaving in and out of traffic to bypass vehicles when he rear-ended a Toyota multi-purpose vehicle near Huli Street at about 12:35 p.m.

The 28-year-old Toyota driver and her 4-month-old daughter were not injured and remained at the scene.

Police said the moped rider was taken in serious condition to a hospital. While at the hospital, his condition worsened to critical condition.

Police noted the rider was not wearing a helmet at the time of the crash.

It’s unknown whether speed was a factor in the crash. Police said alcohol or drugs were not contributing factors.