We reached out to KTC for some information for a project that Vaughn & Melton was working on. Eric and staff were extremely helpful and quick to respond. The information was very detailed and helped us take our project to the next level.

Project Info

Project Request Date: 02/04/2019
Project Requested By: James Ballinger & Courtney Evans – Vaughn Melton
Principle Investigator: William Staats

Initial Inquiry

V&M asked for SPF information for a KYTC project on a two-lane rural route.

Project Write-up

KTC sent Courtney S. Evans the SPF fact sheet for rural, 2-lanes roads as well as the intersection SPF list.

Data Provided

Final Rural Two-Lane SPF and Adjustment Factors

Base Conditions

9’ lanes, 3’ shoulders, Horizontal curvature= Class A, Grade= Class A, no median, no intersections

 

Sample

3119

100-200 intersections*

Length

215.8455

100-200 miles*

Crashes

854

300 crashes per year*

R2

0.515857

Higher values preferred

CDP

13.5941

Less than 5%

MACD

43.40788

Smaller values preferred

MAD

0.355154

Smaller values preferred

Theta

1.531877

Higher values preferred

Alpha

-4.49214

(Intercept) zvalue= 8.77117005270637e-29

Beta

0.844042

lnADT zvalue= 6.2937196537382e-51

StdErr

0.273624

AIC

3581.527

 

 

Lane width AF (Modified from HSM)

Lane Width (ft)

AADT <400

AADT 400-2000

AADT>2000

9 or less (base)

1

1

1

10

0.97

1.02+.000175*(AADT-400)/ 1.05+.000281*(AADT-400)

Or

0.622776+(1302.8/(AADT+3336.65))

0.87

11

0.96

1.01+.000025*(AADT-400)/ 1.05+.000281*(AADT-400)

Or

0.088968+(3261.86/(AADT+3336.65))

0.7

12 or more

0.95

1/(1.05+.000281*(AADT-400))

Or

3558.72/(AADT+3336.65)

0.67

 

Shoulder Width AF (http://www.cmfclearinghouse.org/study_detail.cfm?stid=338)

Shoulder Width

AF

Crash Severity

Roadway Type

Area

0

1.145

All

Two-Lane

Rural

1

1.12

All

Two-Lane

Rural

2

1.03

All

Two-Lane

Rural

3

1

All

Two-Lane

Rural

4

0.975

All

Two-Lane

Rural

5

0.945

All

Two-Lane

Rural

6

0.93

All

Two-Lane

Rural

7

0.905

All

Two-Lane

Rural

8

0.875

All

Two-Lane

Rural

 

Horizontal Curvature AF (http://www.cmfclearinghouse.org/study_detail.cfm?stid=481)

Grade AF (HSM)

Grade

AF

0-3%

1

3-6%

1.1

>6%

1.16

 

Median Installation AF (http://www.cmfclearinghouse.org/detail.cfm?facid=24)

0.88

 

 

Testimonial

 

We reached out to KTC for some information for a project that Vaughn & Melton was working on. Eric and staff were extremely helpful and quick to respond. The information was very detailed and helped us take our project to the next level.

Courtney Evans
Vaughn Melton

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