HUMBLE, Texas — Longtime fleet manager and green transportation advocate Mark Swackhamer has left Houston Independent School District (ISD) to take on a new role at Humble ISD.

Swackhamer had been with Houston ISD for 11 years. He ended his tenure as the district’s senior manager of fleet operations last week.

At Humble ISD, Swackhamer will serve as assistant director of transportation. The district, based about 20 miles north of Houston, transports about 40,000 students to and from 43 schools with a fleet of 267 buses.

At Houston ISD, Swackhamer earned recognition for his efforts to implement alternative fuels and other green initiatives. For example, he helped secure $2.5 million in grants to acquire 27 propane school buses and an 18,000-gallon fueling station in 2011. In 2010, Houston ISD began using biodiesel fuel in all of its diesel school buses and light-fleet vehicles. The district has also added dozens more propane vehicles to its fleet in recent years.

Swackhamer implemented an efficient-driving training program, which aims to avoid hard braking to increase fuel mileage. The district has also used GPS to reduce bus idling and to optimize routes.

In 2012, Houston ISD was chosen as one of SCHOOL BUS FLEET’s Green Fleets Across America. The same year, Swackhamer was named a Sustainability All-Star.

Andres Montes is currently serving as acting senior manager of fleet operations at Houston ISD.