Spatial Transferability of Expansion Factors for Estimating Pedestrian Volume at Intersections.

Area of Science:

• Transportation Engineering
• Urban Planning
• Traffic Data Analysis

Background:

• Estimating annual average daily pedestrian traffic (AADPT) is crucial for developing pedestrian-centric urban strategies.
• The expansion factor method, using continuous counts (CCs) to expand short-term counts (STCs), is standard but requires sufficient CC data, which is often lacking.
• This research addresses the challenge of limited CC data by evaluating the spatial transferability of expansion factors.

Purpose of the Study:

• To assess the spatial transferability of expansion factors for estimating AADPT across different jurisdictions.
• To compare the effectiveness of the single factor method versus modeling methods for transferring expansion factors.
• To identify the conditions under which expansion factor transferability is reliable for pedestrian traffic estimation.

Main Methods:

• Examined spatial transferability of expansion factors across three Ontario (Canada) jurisdictions and one Arizona (USA) jurisdiction.
• Assumed a 'base jurisdiction' with CCs and a 'target jurisdiction' with only STCs, applying factors from the base to the target.
• Tested two approaches: the single factor method (averaging factors) and modeling methods (assigning STC sites to factor groups).

Main Results:

• The single factor method demonstrated acceptable transferability within the similar Ontario jurisdictions, with a minor increase in error (2.3% absolute, 8.7% relative).
• Poor transferability was observed when attempting to transfer factors between jurisdictions with significantly different characteristics (e.g., Ontario to Arizona).
• Modeling methods produced inconsistent results, potentially due to the limited number of sites in the study, warranting further investigation.

Conclusions:

• Spatial transferability of expansion factors is feasible between jurisdictions with similar seasonality and weather patterns.
• Expansion factors are not reliably transferable between jurisdictions with differing characteristics, limiting the application of the single factor method.
• Further research is needed to refine modeling methods for expansion factor transferability, especially with larger datasets.