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21st Century Operations Using 21st Century Technologies

Efficient Use of Highway Capacity Summary
Report to Congress

Notice

This document is disseminated under the sponsorship of the U.S. Department of Transportation in the interest of information exchange. The U.S. Government assumes no liability for the use of the information contained in this document.

The U.S. Government does not endorse products or manufacturers. Trademarks or manufacturers' names appear in this report only because they are considered essential to the objective of the document.

Quality Assurance Statement

The Federal Highway Administration (FHWA) provides high-quality information to serve Government, industry, and the public in a manner that promotes public understanding. Standards and policies are used to ensure and maximize the quality, objectivity, utility, and integrity of its information. The FHWA periodically reviews quality issues and adjusts its programs and processes to ensure continuous quality improvement.

SI* (Modern Metric) Conversion Factors

APPROXIMATE CONVERSIONS TO SI UNITS
SYMBOL WHEN YOU KNOW MULTIPLY BY TO FIND SYMBOL

LENGTH

in

inches 25.4 millimeters mm

ft

feet 0.305 meters m

yd

yards 0.914 meters m

mi

miles 1.61 kilometers km

AREA

in2

square inches 645.2 square millimeters mm2

ft2

square feet 0.093 square meters m2

yd2

square yard 0.836 square meters m2

ac

acres 0.405 hectares ha

mi2

square miles 2.59 square kilometers km2

VOLUME

fl oz

fluid ounces 29.57 milliliters mL

gal

gallons 3.785 liters L

ft3

cubic feet 0.028 cubic meters m3

yd3

cubic yards 0.765 cubic meters m3

NOTE: volumes greater than 1000 L shall be shown in m3

MASS

oz

ounces 28.35 grams g

lb

pounds 0.454 kilograms kg

T

short tons (2000 lb) 0.907 megagrams (or "metric ton") Mg (or "t")
TEMPERATURE (exact degrees)

oF

Fahrenheit

5 (F-32)/9
or (F-32)/1.8

Celsius oC

ILLUMINATION

fc

foot-candles 10.76 lux lx

fl

foot-Lamberts 3.426 candela/m2 cd/m2

FORCE and PRESSURE or STRESS

lbf

poundforce   4.45   newtons N

lbf/in2

poundforce per square inch 6.89 kilopascals kPa

APPROXIMATE CONVERSIONS FROM SI UNITS
SYMBOL WHEN YOU KNOW MULTIPLY BY TO FIND SYMBOL

LENGTH

mm

millimeters

0.039

inches in

m

meters

3.28

feet ft

m

meters

1.09

yards yd

km

kilometers

0.621

miles mi

AREA

mm2

square millimeters

0.0016

square inches in2

m2

square meters

10.764

square feet ft2

m2

square meters

1.195

square yards yd2

ha

hectares

2.47

acres ac

km2

square kilometers

0.386

square miles mi2

VOLUME

mL

milliliters

0.034

fluid ounces fl oz

L

liters

0.264

gallons gal

m3

cubic meters

35.314

cubic feet ft3

m3

cubic meters

1.307

cubic yards yd3

MASS

g

grams

0.035

ounces oz

kg

kilograms

2.202

pounds lb

Mg (or "t")

megagrams (or "metric ton")

1.103

short tons (2000 lb) T

TEMPERATURE (exact degrees)

oC

Celsius 1.8C+32 Fahrenheit oF

ILLUMINATION

lx

lux

0.0929

foot-candles fc

cd/m2

candela/m2

0.2919

foot-Lamberts fl

FORCE and PRESSURE or STRESS

N

newtons 0.225 poundforce lbf

kPa

kilopascals

0.145

poundforce per square inch lbf/in2

*SI is the symbol for the International System of Units. Appropriate rounding should be made to comply with Section 4 of ASTM E380.
(Revised March 2003) Return to footnote 2.

Technical Report Documentation Page

1. Report No.

FHWA-HOP-10-023

2. Government Accession No.

3. Recipient's Catalog No.

4. Title and Subtitle

EFFICIENT USE OF HIGHWAY CAPACITY SUMMARY

5. Report Date

May 2010

6. Performing Organization Code

HOP

7. Author(s)

Beverly Kuhn

8. Performing Organization Report No.

Report

9. Performing Organization Name and Address

Texas Transportation Institute
The Texas A&M University System
College Station, Texas 77843-3135

10. Work Unit No.

 

11. Contract or Grant No.

Project No. DTFH61-06-D-00007

12. Sponsoring Agency Name and Address

U.S. Department of Transportation
Federal Highway Administration
Office of Operations (HOP)
Mail Stop: E86-205
1200 New Jersey Avenue, SE
Washington, DC 20590

13. Type of Report and Period Covered

Technical

14. Sponsoring Agency Code

FHWA

15. Supplementary Notes

Project performed in cooperation with the U.S. Department of Transportation, Federal Highway Administration.
Project Title: Efficient Use of Highway Capacity Summary

16. Abstract

This report was developed to summarize the implementation of safety shoulders as travel lanes as a method to increase the efficient use of highway capacity. Its purpose is to provide a succinct overview of efforts to use left or right shoulder lanes as temporary or interim travel lanes. As part of this summary, information related to the impact of that shoulder usage on highway safety and/or accidents during operations was reviewed as well. The intent of the report is to provide critical information that the Federal Highway Administration (FHWA) can use to formulate guidance for agencies on providing temporary shoulder use as a means of increasing roadway capacity. The study that generated this product was conducted at the request of Congress through the 2008 Technical Corrections Act. Those issues that need to be considered include design, traffic control devices, performance measures, potential safety benefits, maintenance concerns, enforcement roles and processes, incident response, training for personnel, costs, liability and legal issues, and public outreach and education. Careful consideration of these issues can help ensure a shoulder use deployment is effective without having negative impacts on safety and operations.

17. Key Words

Highway capacity, safety shoulder, temporary shoulder use, safety, operations, managed lanes, HOT lanes, HOV lanes, geometric design, active traffic management

18. Distribution Statement

No restrictions. This document is available to the public through the FHWA Freeway Management Program website: http://ops.fhwa.dot.gov/freewaymgmt/mngd_lns_hov.htm

19. Security Classif. (of this report)

Unclassified

20. Security Classif.
(of this page)

Unclassified

21. No of Pages

96

22. Price

 

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