Seattle Pedestrian Advisory Board
July 30, 2002
Council Member Richard Conlin
Dear Council Member Conlin
Re/I-90 Bridge bicycle/pedestrian pathway facility:
On September 7, 2000 the Seattle Pedestrian Advisory Board (SPAB) addressed a letter to Transportation Committee Chair. Richard McIver opposing Alternative R-8, narrowing the single, two-way, bicycle/pedestrian pathway facility on the I-90 Bridge from ten feet to eight feet in order to incorporate east-bound and west-bound HOV or transit lanes. SPAB also opposed reduction of shoulder safety separation width between high speed vehicular traffic and pedestrians.
SPAB continues its opposition to an eight-foot bicycle/pedestrian facility and narrow, unsafe shoulder separation. Now we advise the Council Transportation Committee to oppose Alternatives R5 and R8-A in so far as they reduce the pathway width from ten feet to eight feet and narrow the shoulder separation to two feet.
Such a reduced pathway and separation would violate the AASHTO standards set out in the AASHTO design manual and the Seattle Comprehensive Plan, both of which call for ten-foot pathways.
SPAB recommends a twelve-foot pathway. Current trends in the use of the I-90 Bridge pathway will within the 50-year lifetime of the bridge result in more than 600 users per hour at peaks. AASHTO standards require that a pathway greater than ten feet in width be provided for a facility carrying in excess of 600 users per hour.
SPAB recommends maintaining the eight-foot protective shoulder. A double trailer semi-truck passing either cyclists or pedestrians less than eight feet away could have a detrimental and destabilizing effect on pathway users.
Finally, as a matter of public policy SPAB supports pedestrianism as an alternative mode of transportation which should be encouraged, not discouraged by downgrading pedestrian pathways on major bridge facilities to favor vehicular mobility.
We ask that you, as Chair. of the Council Transportation Committee, work to ensure that the I-90 Bridge Alternatives R-5 and R-8A and their successors do not reduce the width of the bicycle/pedestrian pathway from ten feet to eight feet and do maintain a four to eight foot width of protective shoulder between vehicle lanes and the pathway.. All solutions to the I-90 Bridge should increase, not decrease pedestrian safety and mobility.
Charles R. Smith,
cc: Council Members of the Transportation Committee