men attaching emissions equipment to a bus


The objective of this test is to provide accurate, comparable gas and particulate emissions data for transit buses produced by different manufacturers while operating the vehicle over a simulated transit duty cycle on a dynamometer [download full test procedure]. The test will be performed on a engine after the bus has accumulated several thousand miles of operation, thus providing a more realistic indication of the level of emissions that can be expected in actual transit service. The results of this test may be used by transit operators for making relative comparisons between buses. The test is performed using a large-roll chassis dynamometer. 

Please Note: This is not the same procedure that is used to meet the Environment Protection Agency (EPA) for engine certification. 



Established in 1989 by the Pennsylvania Transportation Institute with funding provided by the Federal Transit Administration, the Larson Transportation Institute’s Bus Research and Testing Center tests buses for safety, structural integrity, durability, performance, maintainability, noise, emissions, energy economy, and fuel economy. Based primarily in Altoona, Pennsylvania, the Center also has a facility located at the Larson Transportation Institute Test Track in Bellefonte, Pennsylvania.  

Bus Research and Testing Center

2237 Plank Road

Duncansville, PA 16635

Phone: 814-695-3404

Fax: 814-695-4069