Proterra Inc. submitted a model BE35, electric-powered 34 seat/35-foot bus, for a partial STURAA test in the 12 yr/500,000 mile category. The Federal Transit Administration determined that the following tests would be performed: 4.1 Performance, 4.2 Brake Test, 6. Fuel Economy Test (Energy Economy/Range Test) and 7.2 Exterior Noise. Testing started on March 14, 2013 and was completed on May 1, 2013. The Check-In section of the report provides a description of the bus and specifies its major components.
The interior of the bus is configured with seating for 34 passengers including the driver. Free floor space will accommodate 27 standing passengers resulting in a potential load of 61 persons. At 150 lbs per person, this load results in a measured gross vehicle weight of 37,530 lbs.
Effective January 1, 2010 the Federal Transit Administration determined that the total number of simulated passengers used for loading all test vehicles will be based on the full complement of seats and free-floor space available for standing passengers (150 lbs per passenger). The passenger loading used for dynamic testing will not be reduced in order to comply with Gross Axle Weight Ratings (GAWR’s) or the Gross Vehicle Weight Ratings (GVWR’s) declared by the manufacturer. Cases where the loading exceeds the GAWR and/or the GVWR will be noted accordingly. During the testing program, all test vehicles transported or operated over public roadways will be loaded to comply with the GAWR and GVWR specified by the manufacturer.
The performance of the bus is illustrated by a speed vs. time plot. Acceleration and gradeability test data are provided in Section 4, Performance. The average time to obtain 50 mph was 42.97 seconds. The Stopping Distance phase of the Brake Test was completed with the following results; for the Uniform High Friction Test average stopping distances were 32.74’ at 20 mph, 65.64’ at 30 mph, 120.76’ at 40 mph and 151.81’ at 45 mph. The average stopping distance for the Uniform Low Friction Test was 31.07’. There was no deviation from the test lane during the performance of the Stopping Distance phase. During the Stability phase of Brake Testing the test bus experienced no deviation from the test lane but did experience pull to the left during both approaches to the Split Friction Road surface. The Parking Brake phase was completed with the test bus maintaining the parked position for the full five minute period with no slip or roll observed in both the uphill and downhill positions.
An energy Economy/Range Test was run on simulated central business district, arterial, and commuter courses. The results are listed in Section 6. of this report.
A series of Interior and Exterior Noise Tests was performed. These data are listed in Section 7.1 and 7.2 respectively.
The Emissions Test was performed. These results are available in Section 8 of this report.