annual average daily traffic MUTCD 2009 Edition with May 2012 Revisions 1 and 2

American Association of State Highway and Transportation Officials MUTCD 2009 Edition with May 2012 Revisions 1 and 2

The rate at which the centripetal acceleration necessary to negotiate a horizontal curve is developed on the transition segment leading up to the curve.

A device that communicates information about pedestrian signal timing in non-visual format such as audible tones, speech messages, and/or vibrating surfaces. MUTCD 2009 Edition with May 2012 Revisions 1 and 2

A device designated to assist the pedestrian who has visual or physical disabilities in activating the pedestrian phase. MUTCD 2009 Edition with May 2012 Revisions 1 and 2

The flashing-light signals, with or without warning gates, together with the necessary control equipment used to inform road users of the approach or presence of rail traffic at grade crossings. MUTCD 2009 Edition with May 2012 Revisions 1 and 2

 The sight distance provided by the highway as designed.

A type of traffic control signal operation in which some or all signal phases are operated on the basis of actuation. MUTCD 2009 Edition with May 2012 Revisions 1 and 2

Initiation of a change in or extension of a traffic signal phase through the operation of any type of detector. MUTCD 2009 Edition with May 2012 Revisions 1 and 2