Snow Lab Experiment:
Staff will be implementing a Snow Lab Experiment during the second and third weeks of January, 2017. The experiment will mimic the project’s proposed curb locations utilizing temporary, candlestick bollards. The experiment will assess the vehicle movement, snow removal and RFTA bus movement on the north side of Hallam Street during heavy snow periods. More details will be provided as the project proceeds.
The Living Lab Experiment will temporarily modify the layout of the existing bridge to incorporate a widened sidewalk on the north side of the bridge giving drivers, pedestrians, and bicyclists an opportunity to experience the new configuration and will allow staff to study the impacts of the changes.
The Living Lab will implement a temporary concrete infill to extend the existing walk on the north side of Castle Creek Bridge. The extension will allow for improved opposing movement between pedestrian and bicycle use on the walk. Users for the walk will have additional protection from vehicular traffic with the use of white, water filled jersey barriers that will separate the moving vehicles from the users.
Please see below for updated detour routes and maps.
A goal for Staff is to increase the pedestrian and bicycle safety while having little impact on vehicular movement on the bridge. The increase in the bike path without the ability to widen the bridge will decrease the travel lanes from the existing 12 feet of width down to 11 feet of width. The experiment will study the vehicular movements through an outside consultant on three different occasions during the length of the Living Lab to verify the impact of decreasing the lane width to 11 feet on vehicular traffic. Staff will utilize data summarized below to compare with the experiment flow and use.
Prior to beginning the Living Lab Experiment, Fox Tuttle Hernandez Transportation Group studied vehicular movements on Castle Creek Bridge. The study indicates that approximately 27,100 vehicles per day cross Castle Creek Bridge and the 85th percentile speed was 24 to 26 miles per hour. Fox Tuttle Hernandez does not anticipate traffic to be impacted by the reduction of lane drive widths by 1 foot.
Several national studies have been implemented to study the impact on traffic that reducing lane width would have. A few summaries are provided below:
“All projects evaluated during the study that consisted exclusively of lane widths of 10 feet or more resulted in accident rates that were either reduced or unchanged.”
Effective Utilization of Street Width on Urban Arterials
“So long as all other geometric and traffic signalization conditions remain constant, there is no measurable decrease in urban street capacity when through lane widths are narrowed from 12 feet to 10 feet.”
Past Chair of the TRB Highway Capacity and
Quality of Service Committee Synthesis of Recent Study Results
Construction for the Living Lab will begin in April and the duration is anticipated to go until the end of July. Dates will be updated for the Living Lab.
Bridge Detour Route: