Spatial weight matrix:
ADA Curb Ramp Demand Prioritization Model
2017 Xiaochen Chen
Introduction
Over the next 25 years, IDOT aims to achieve 100% ADA compliance on all roadways within their jurisdiction. IDOT approached CMAP to develop a model tool that would quantify demand for ADA compliance and thus help them prioritize corridors for improvement. Although ADA compliance is based on a variety of factors such as curb ramps, audible signals, crosswalks, and sidewalks. IDOT asked CMAP to focus on evaluating the demand for ADA compliant curb ramps, with particular attention paid to curb ramps that are currently non-compliant.
Project Goals
Identify the locations of non-compliant ADA Curb Ramps within a user-defined distance from highways in IDOT’s jurisdiction and attach attribute data from three factors (transit ridership, destinations like stores, schools, hospitals, etc., and ADA demographics) to each curb ramp point.
Quantify the importance of addressing curb ramps by normalizing the data from the three factors to generate a curb level prioritization score.
Aggregate the curb level prioritization scores to corridor level prioritization scores by a user defined distance from each roadway.
Methodology
Prioritization Score of Curb Ramps = Transit Accessibility Score + Destination Accessibility Score + ADA Demographics Score
Prioritization Score of Target Corridors = Sum the prioritization score of curb ramps within 160-foot buffer of target corridors
Prioritization Score per Mile of Target Corridors = Prioritization score of target corridors / Length of target corridor
Delivery
This study provides a method to verify real time probe incident data and explores the impact of expressway incidents on traffic congestion, include duration, speed reduction, impact distance. Impact analysis reveals fatal and serious injury incidents will reduce 50% faster average travel speed, average duration of decelerations associated with fatal incidents 3.5 hours and with serious injury incidents1 hour. Affected mileage varies large, but the collision will cause the speed to be reduced 9 miles long.
