Memorandum

TO:	All Design Section Staf
FROM:	C. C. Ruth
DATE:	November 1, 2000
SUBJECT:	BDM, Section 8.3.2-1 Bridge Traffic Barriers

Section 8.3.2A is supplemented with the following:

6. When designing and detailing bridge traffic barrier orientation on a superelevated bridge deck, the following guidelines shall be used:

a. For bridge decks with a superelevation of 8% or less, the traffic barriers
(and the median barrier, if any) shall have an orientation that is perpendicular to the bridge deck.

             b. For bridge decks with a superelevation of more than 8%, the traffic barrier on the low side of the
                 bridge (and median barrier, if any) shall have an orentation that is perpendicular to an 8% superelevated
                 bridge deck. For this situation, the traffic barrier on the high side of the bridge shall have an orientation
                 that is perpendicular to the bridge deck.

Background

When the superelevation of a bridge deck exceeds 8%, the effectiveness of the bridge traffic barrier oriented perpendicular to the bridge deck on the low side of the bridge is diminished. The above guidelines have been discussed with and approved by the Dick Albin in the Design Office and Dennis Elkhart, the FHWA Safety Engineer.

CCR

cc: J. A. Weigel - 47340
Rick Brice - 47340