All northbound lanes were closed until around 7:30 am as police investigated the incident, which began just before 6:00 am.
San Antonio Police spokesman Sergeant Javier Salazar said "Witnesses report that there was a motorcycle weaving in and out of traffic, driving irratically at a high rate of speed. Reportedly the motorcycle struck the rear of a pickup truck".
The motorcyclist was killed instantly following the impact, which sent the truck rolling across several lanes into the access road. The truck driver was hospitalized with non life threatening injuries.
Salazar added that all northbound lanes of I-35 were closed until around 7:30 am while police investigated the incident.
By Johnny Shannon