Project Info

Project Request Date: 10/01/2018
Project Requested By: Michael Vaughn, PE – Highway Safety Improvement Program
Principle Investigator: William Staats

Initial Inquiry

 

Below are the two primary items I would like evaluated. If you can think of other aspects of this countermeasure that can be evaluated, by all means evaluate them.

1. The targeted crash type was Roadway Departure crashes. So, was the Edgeline Only Striping countermeasure effective at reducing Roadway Departure crashes and to what degree? If you can, calculate a Benefit/Cost ratio similar to how you would calculate a B/C ratio if it were being included in the Annual Report (which we will do in the next year’s Annual Report).

2.  I would want to know if the edgeline only striping had any effect on head-ons and sideswipes. I highly doubt this countermeasure would increase head-ons and sideswipes, but I have no scientific evidence to refute the claim.

In short, I’m hoping we can show this countermeasure as having great benefit, with little, to no increase in head-ons and sideswipes.

Project Write-up

I have redone the Wilcoxon tests for KAB and KA crashes. Nothing showed a statistically significant change in proportion between the before and after period for KAB or KA crashes. However, a few scenarios occurred where all sites that did have a change in crash proportion for a particular group either all increased or decreased, but there were too few sites that changed to be able to say the change was statistically significant. Here are the summary tables for the new tests.

Data Provided

Here are summary tables for the lengths and 2016/2017 crashes for rural two-lanes, urban two-lanes, and both combined. 

Rural Two-Lanes

AADT

 

<400

400<=x<1000

1000<=x<3000

>=3000

Total

 

Total Mileage

8390.978

3766.568

5501.116

2764.73

20423.392

2016&2017 Crashes

Fatal Crashes

49

120

243

228

640

Injury Crashes

1027

2087

4685

4466

12265

PDO Crashes

2728

5926

13012

15042

36708

 

Total Crashes

3804

8133

17940

19736

49613

 

Urban Two-Lanes

AADT

 

<400

400<=x<1000

1000<=x<3000

>=3000

Total

 

Total Mileage

174.554

176.856

689.101

1880.011

2920.522

2016&2017 Crashes

Fatal Crashes

0

4

14

151

169

Injury Crashes

213

114

877

8513

9717

PDO Crashes

1342

522

4405

41017

47286

 

Total Crashes

1555

640

5296

49681

57172

 

All Two-Lanes

AADT

 

<400

400<=x<1000

1000<=x<3000

>=3000

Total

 

Total Mileage

8565.532

3943.424

6190.217

4644.741

23343.914

2016&2017 Crashes

Fatal Crashes

49

124

257

379

809

Injury Crashes

1240

2201

5562

12979

21982

PDO Crashes

4070

6448

17417

56059

83994

 

Total Crashes

5359

8773

23236

69417

106785

The Kentucky Traffic Safety Data Service (KTSDS) is a program of the Kentucky Transportation Center.
176 Raymond Building, University of Kentucky, Lexington KY 40506.

Copyright © 2018 Kentucky Transportation Center, University of Kentucky.