Author: Richard Storm
Publisher:
ISBN:
Category : Speed limits
Languages : en
Pages : 0
Book Description
The objective of this study was to evaluate the safety impacts of increasing the speed limit from 55 mph to 60 mph on two-lane, two-way state highway road segments in Minnesota. An empirical Bayes (EB) before-after analysis was used to estimate crash modification factors (CMFs) for both segments and intersections. The segment analysis showed an 8 percent reduction in total crashes that was statistically significant, alongside a significant 15 percent increase in combined fatal, serious injury, and minor injury (KAB) injury crashes. The range of most of the segment CMFs hovered close to 1. The intersection analysis was split into two groups (all traffic control types and thru-stop control only). The aggregate CMFs for all intersections within these two groups showed, on average, between a 10% and 20% statistically significant reduction in total and injury crashes. Analysis was also performed on four subgroups (3- and 4-leg, lighting/no lighting) within the two main intersection groups. Disaggregating the intersections into further groups led to smaller sample sizes that led to higher standard errors showing a widespread range of CMFs around 1 for the individual crash types and severities. The aggregate estimated crash safety effects (for total and injury crashes) for combined segments and intersection sites showed a reduction in total crashes but an increase in the KAB injury crashes.
Speed Limit Change (55 Mph to 60 Mph) Safety Re-evaluation
Author: Richard Storm
Publisher:
ISBN:
Category : Speed limits
Languages : en
Pages : 0
Book Description
The objective of this study was to evaluate the safety impacts of increasing the speed limit from 55 mph to 60 mph on two-lane, two-way state highway road segments in Minnesota. An empirical Bayes (EB) before-after analysis was used to estimate crash modification factors (CMFs) for both segments and intersections. The segment analysis showed an 8 percent reduction in total crashes that was statistically significant, alongside a significant 15 percent increase in combined fatal, serious injury, and minor injury (KAB) injury crashes. The range of most of the segment CMFs hovered close to 1. The intersection analysis was split into two groups (all traffic control types and thru-stop control only). The aggregate CMFs for all intersections within these two groups showed, on average, between a 10% and 20% statistically significant reduction in total and injury crashes. Analysis was also performed on four subgroups (3- and 4-leg, lighting/no lighting) within the two main intersection groups. Disaggregating the intersections into further groups led to smaller sample sizes that led to higher standard errors showing a widespread range of CMFs around 1 for the individual crash types and severities. The aggregate estimated crash safety effects (for total and injury crashes) for combined segments and intersection sites showed a reduction in total crashes but an increase in the KAB injury crashes.
Publisher:
ISBN:
Category : Speed limits
Languages : en
Pages : 0
Book Description
The objective of this study was to evaluate the safety impacts of increasing the speed limit from 55 mph to 60 mph on two-lane, two-way state highway road segments in Minnesota. An empirical Bayes (EB) before-after analysis was used to estimate crash modification factors (CMFs) for both segments and intersections. The segment analysis showed an 8 percent reduction in total crashes that was statistically significant, alongside a significant 15 percent increase in combined fatal, serious injury, and minor injury (KAB) injury crashes. The range of most of the segment CMFs hovered close to 1. The intersection analysis was split into two groups (all traffic control types and thru-stop control only). The aggregate CMFs for all intersections within these two groups showed, on average, between a 10% and 20% statistically significant reduction in total and injury crashes. Analysis was also performed on four subgroups (3- and 4-leg, lighting/no lighting) within the two main intersection groups. Disaggregating the intersections into further groups led to smaller sample sizes that led to higher standard errors showing a widespread range of CMFs around 1 for the individual crash types and severities. The aggregate estimated crash safety effects (for total and injury crashes) for combined segments and intersection sites showed a reduction in total crashes but an increase in the KAB injury crashes.
An Evaluation of the 55 Mph Speed Limit Enforcement Demonstration Projects in Connecticut and Utah
Author: Terry M. Klein
Publisher:
ISBN:
Category :
Languages : en
Pages : 40
Book Description
Publisher:
ISBN:
Category :
Languages : en
Pages : 40
Book Description
Review of Information on the Safety Effects of the 55 Mph Speed Limit in the U.S.
Author: D. F. Mela
Publisher:
ISBN:
Category : Speed limits
Languages : en
Pages : 90
Book Description
Publisher:
ISBN:
Category : Speed limits
Languages : en
Pages : 90
Book Description
The Effectiveness of the 55 Mph National Maximum Speed Limit as a Life Saving Benefit. Executive Summary
Effects of the 55 Mph Speed Limit
Author: American Association of State Highway and Transportation Officials. Operating Subcommittee on Traffic Engineering
Publisher:
ISBN:
Category : Speed limits
Languages : en
Pages : 66
Book Description
Publisher:
ISBN:
Category : Speed limits
Languages : en
Pages : 66
Book Description
55 mph fact book
Author: United States. National Highway Traffic Safety Administration. Enforcement and Emergency Services Division
Publisher:
ISBN:
Category :
Languages : en
Pages : 60
Book Description
Publisher:
ISBN:
Category :
Languages : en
Pages : 60
Book Description
The 55-MPH Speed Limit
Author: United States. Congress. House. Committee on Science and Technology. Subcommittee on Transportation, Aviation, and Materials
Publisher:
ISBN:
Category : Speed limits
Languages : en
Pages : 372
Book Description
Publisher:
ISBN:
Category : Speed limits
Languages : en
Pages : 372
Book Description
The National Maximum Speed Limit
Author: Traffic Safety Programs (U.S.)
Publisher:
ISBN:
Category : Automobiles
Languages : en
Pages : 200
Book Description
Publisher:
ISBN:
Category : Automobiles
Languages : en
Pages : 200
Book Description
Impact and Implementation of the 55-mile-per-hour Speed Limit
Author: United States. Congress. House. Committee on Public Works and Transportation. Subcommittee on Surface Transportation
Publisher:
ISBN:
Category : Speed limits
Languages : en
Pages : 842
Book Description
Publisher:
ISBN:
Category : Speed limits
Languages : en
Pages : 842
Book Description
The National Highway Safety Needs Report
Author: United States. Department of Transportation
Publisher:
ISBN:
Category : Roads
Languages : en
Pages : 160
Book Description
Publisher:
ISBN:
Category : Roads
Languages : en
Pages : 160
Book Description