Houston ISD received grants for 27 propane buses and a fueling station. Here, Ramon Vazquez fills one of the buses with the alternative fuel.
Houston Independent School District
Going green, saving green
With its vehicles traveling more than 21 million miles each year, Houston Independent School District (ISD) has the potential to generate huge savings in the area of fuel use.
“Going green has a dual benefit,” says Nathan Graf, general manager of transportation. “Fewer toxins are released into the air, thereby supporting a healthier environment for our students and community, and it is also cost-effective, allowing more dollars to be used in the classroom from reduced fuel costs.”
Alternative fuels are a key part of the green undertaking. Last year, the district was awarded $2.5 million in grants for 27 propane-powered school buses and an 18,000-gallon fueling station. An additional 20 propane vans are on order, and a grant application has been submitted for 70 more propane buses.
All of Houston ISD’s diesel-powered units run on a B5 blend of biodiesel. “That alone offsets our petroleum use by 105,000 gallons per year,” says Mark Swackhamer, senior manager of fleet operations.
The district also recently brought its first hybrid vehicles into the fleet with a purchase of 12 units. An additional 16 hybrids are on order, two of which will be tested in the district’s police department.
Swackhamer says that Houston ISD’s propane buses have reduced diesel usage by about 54,000 gallons per year. With propane’s lower fuel costs per mile, the result has been a savings of $74,900. Meantime, the district’s hybrid vehicles have cut fuel costs by $23,927.
Reducing idling is another significant element of Houston ISD’s green transportation efforts. The district’s school buses, support fleet and police department vehicles are equipped with GPS/telematics, which “is used to track idle time, route efficiencies and on-time performance to schools and bus stops — along with dispatching and monitoring of service and safety personnel,” Swackhamer says.
The transportation department at Houston ISD has gone green in a number of ways, from adopting alternative fuels to reducing idling to increasing efficiency.
In November, Houston ISD launched an extensive no-idle campaign for its school buses, with daily reports and progress tables being sent to each school bus motor pool and to upper management. The reports track bus idle time in excess of five minutes for each bus and overall for each motor pool.
“Drivers with excessive idle time were counseled, and overall idle time was reduced by 40 percent [or 8,556 hours] in a three-month period,” Swackhamer says, noting that this has equated to a decrease of 56 tons of greenhouse gases.
The district has further decreased emissions by installing more than 490 particulate traps and closed crankcase ventilation filters on its buses.
GPS has also been used with routing and scheduling software to cut the number of bus routes from 868 to 824 — while increasing ridership by more than 1,500 students. Correspondingly, 53 buses were taken out of the active fleet.
Swackhamer says that the routing and fleet reductions have saved about $1.8 million in fuel, salaries and maintenance costs.
Another green initiative at Houston ISD targets changing driver behavior. Using the GPS system, the district has developed a report that shows each time a vehicle has a “hard brake” event (with the threshold being nine feet per second).
Initially, 20 vehicles were monitored without the drivers’ knowledge. Those who were found to be outside of the norm, in terms of miles between hard braking events, were notified.
“I informed the driver that this was just an informational call and would hope that they would become more aware of their driving habits,” Swackhamer says.
Most of the drivers who were contacted then shifted from an average of three miles between events to 10 miles between events. One driver went up to 27 miles between events.
— THOMAS MCMAHON
School buses: 996
Alternative fuels used: Propane, biodiesel
Students transported daily: 29,500
Schools served: 300
Transportation staff: 1,200
Area of service: 310 sq. miles