Michael Wehr, Director of Maintenance
Milwaukee County Transit System
1942 North 17th Street
Milwaukee, WI 53205-1697
Dear Mr. Wehr:
This responds to your letter asking about Federal Motor Vehicle Safety Standard (FMVSS) No. 102, Transmission shift lever sequence, starter interlock, and transmission braking effect.
According to your letter, the Milwaukee County Transit System purchases transit buses. You state that for years, new buses could be purchased with a transmission shift selector in the form of a horizontal row of three buttons: "D" for forward; "N" for neutral; and "R" for reverse. Recently, the bus manufacturer has begun to only offer buses with a shift selector in the form of a vertical row of six buttons, which are, from top to bottom: "R" for reverse; "N" for neutral; "D" for forward; "3" for third gear; "2" for second gear; and "1" for first gear.
You believe the bus manufacturer no longer offers the older system because bus manufacturers and transmission suppliers have recently changed their interpretation of FMVSS No. 102. According to your letter, they have taken the position that "in order to comply with [FMVSS No. 102] the bus operator has to be able to manually downshift the automatic transmission on a transit bus." You ask whether new transit buses can be produced with the older three-button shift selector system.
As we have explained in a previous interpretation letter, FMVSS No. 102 "does not require more than one forward drive shift lever position," provided that engine braking occurs automatically at speeds below 40 km/h. See letter to Arnold and Porter dated August 13, 1987, (copy enclosed). Thus, a bus could be produced with a transmission that only included the D, N and R shift positions rather than R, N, D, 3, 2, and 1, so long as the rest of the standards requirements were met. We note that the transmission retarder on your buses that is activated by the service brake pedal would not satisfy the standards requirements.
We do not have sufficient information to comment on why particular bus manufacturers and transmission suppliers may believe that buses with the older three-button shift selector system may not comply with FMVSS No. 102. If they have any questions about the standard, they may contact us.
I hope this information is helpful. If you have any further questions, please feel free to contact Dorothy Nakama of my staff at this address or at (202) 366-2992.