Research Support to INDOT on I-465 Southeast Variable Speed Limit and Ramp Meter Project

Details

• Creators:
  Desai, Jairaj C. ; Gartner, Christopher ; Sakhare, Rahul Suryakant ; Cox, Edward D. ; Sturdevant, James R. ; Bullock, Darcy M.
• Corporate Creators:
  Purdue University. Joint Transportation Research Program
• Corporate Contributors:
  Indiana Department of Transportation ; United States. Department of Transportation. Federal Highway Administration
• Subject/TRT Terms:
  Before And After Studies Braking Connected Vehicles Crash Data Evaluation Performance Ramp Metering Safety Variable Speed Limits
• Publication/ Report Number:
  FHWA/IN/JTRP-2025/32
• DOI:
  https://doi.org/10.5703/1288284318592
• Resource Type:
  Tech Report
• Geographical Coverage:
  United States ; Indiana
• Edition:
  Final Report
• Corporate Publisher:
  Purdue University. Joint Transportation Research Program
• Abstract:
  Traditionally, crash data, crash risk models, video recordings and user surveys have been utilized by agencies to measure the safety benefits of ramp metering technology. Connected vehicle data can now provide an agile evaluation alternative for quantifying impact of ramp meter deployments. Furthermore, in contrast to crash data, connected vehicle near miss events occur much more frequently, so the before-after evaluation can be conducted over a much shorter time period consisting of a few months, or perhaps even a few weeks. Indiana deployed ramp meters on the southeast section of I-465 around Indianapolis, on or around May 14, 2024, which were then active primarily during the morning and evening peak hours. Additionally, Indiana deployed Variable Speed Limit (VSLs) on September 10, 2024, at 25 locations on I-465. This study was initiated to evaluate the impact of those deployments. Hard-braking events, a surrogate safety performance measure, were estimated from high-frequency connected vehicle data available at 3-second fidelity for vehicles passing through the metered ramps and the adjacent mainline interstate. A before-after analysis for the 4-5 PM peak hour showed approximately a 61% reduction in hard-braking events on mainline merge areas adjoining the metered ramps on the inner loop of I-465. Spatial analysis also showed a 70%, 41%, and 33% median reduction in mild, moderate, and severe hard-braking events per 0.1-mile segment in the entire 7.5-mile mainline corridor adjacent to metered ramps. A before-after analysis of the 10 AM–1 PM hours showed little to modest impact on speeds in 0.3-mile evaluation sections with VSL deployments. The methodologies and performance measures provided in this paper present a framework that scales well to systematically assess and document the performance of new ramp metering and VSL deployments.
• Format:
  PDF
• Funding:
  SPR-4636
• Collection(s):
  US Transportation Collection
• Main Document Checksum:
  urn:sha-512:135b659235ed8892ce9751001df162a318f5f2032c89ebf8039218d3cf8259d0a6262e3dde39fd85ad34b915194dbba4604972dc7bf5f5eb5dfdc1839ea447a0
• Download URL:
  https://rosap.ntl.bts.gov/view/dot/90698/dot_90698_DS1.pdf
• File Type:
  [PDF - 9.34 MB ]