Memorandum - NHTSA

IV-7
Tillman and Figure W-2taken from that referen~e).~Measurements are to be made at the fixc:d
operator position at the lift controls and anywhere on the lift platform.
VRTC measured 85 dBA ambient noise at 305 mm (1’) from a Braun Lift electric motor and 7 3
dBA and 75 dBA, respectively, for a TMC bus lift being raised and interior ambient noise wit1 L
the engine running. Also, VRTC measured the ambient noise levels at 6 bus stops and found iiin
average of 79 dBA. The 75 dBA level has been used by the San Diego Transit Corporation in its
lift specifications and was adopted by FTA in their guidelines for both passive and active lifts.
The 85 dBA warning signal outside the bus would be completed within 4-8 seconds and woulcl.
not interfere with, or contribute to, the 80 dBA maximum allowable equipment operating nois :
level. This maximum noise level does not apply to the deploying or stowing aspects of the lif I.
equipment when the lift platform is unoccupied. A maximum lift noise level is not contained
the Access Board’s final guidelines. It is believed that all lift equipment would comply, hence 1 io
cost impact is anticipated.
4 The Vehicle Research and Test Center (VRTC) is located in East Liberty, OH and is
part of NHTSA’s Office of Research and Development.