Recurring Traffic Bottlenecks: A Primer
Focus on Low-Cost Operational Improvements (Fourth Edition)

Foreword

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. This report does not constitute a standard, specification, or regulation.

The U.S. Government does not endorse products or manufacturers. Trademarks or manufacturers' names may 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. FHWA periodically reviews quality issues and adjusts its programs and processes for continuous quality improvement.

Technical Report Documentation Page

1. Report No.

FHWA-HOP-18-013

2. Government Accession No.

3. Recipient's Catalog No.

4. Title and Subtitle

Recurring Traffic Bottlenecks: A Primer, Focus on Low-Cost Operational Improvements, Fourth Edition

5. Report Date

November 2017

6. Performing Organization Code

7. Author(s)

Neil Spiller, Katherine Blizzard, Rich Margiotta, Ph.D.

8. Performing Organization Report No.

9. Performing Organization Name and Address

Cambridge Systematics, Inc.
3 Bethesda Metro Center, Suite 1200
Bethesda, MD 20814

10. Work Unit No. (TRAIS)

11. Contract or Grant No.

DTFH61-12-D-00048

12. Sponsoring Agency Name and Address

U.S. Department of Transportation
Federal Highway Administration
Office of Operations
1200 New Jersey Avenue, SE
Washington, DC 20590

13. Type of Report and Period Covered

Final research report

14. Sponsoring Agency Code

FHWA HOP

15. Supplementary Notes

Government Task Manager: Neil Spiller

16. Abstract

While many of the nation's bottlenecks are addressed through costly major construction projects (i.e., "megaprojects") or costly transportation alternative solutions (e.g., high occupancy vehicle (HOV) or high occupancy toll (HOT) lanes, dynamic pricing, investments in transit alternatives, parking and commuter incentive programs, etc.) there is a significant opportunity for the greater application of operational and low-cost "fixes" at spot-specific locations.

This primer is the signature product of the Localized Bottleneck Reduction (LBR) Program, which is administered out of the Office of Operations at the Federal Highway Administration (FHWA) headquarters in Washington, D.C. The LBR program is focused on relieving recurring congestion chokepoints (as opposed to nonrecurring congestion causes) and the operational influences that cause them with lower cost, less intensive means. This is the updated, fourth edition of this primer. The first version is FHWA-HOP-07-130, the second version is FHWA-HOP-09-037, and the third version is FHWA-HOP-12-012. The first and second editions of this primer introduced, and then raised awareness about, how LBR strategies could deal with congestion, respectively. The third edition focused on providing highly specific guidance for agencies to follow in developing and advancing LBR programs. This fourth edition builds upon and updates the previous editions with recent advances in innovative research and additional case studies of implementing LBR strategies.

17. Key Words

bottleneck, localized bottleneck reduction, chokepoint, recurring congestion, low cost improvements, operational deficiencies, lane drops, weaves, merges, metering

18. Distribution Statement

No restrictions

19. Security Classif. (of this report)

Unclassified

20. Security Classif. (of this page)

Unclassified

21. No of Pages

22. Price

N/A

Form DOT F 1700.7 (8-72)

Reproduction of completed pages authorized

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)
°F	Fahrenheit	5 (F-32)/9 or (F-32)/1.8	Celsius	°C
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)
°C	Celsius	1.8C+32	Fahrenheit	°F
Illumination
lx	lux	0.0929	foot-candles	fc
cd/m²	candela/m²	0.2919	foot-Lamberts	fl
Force and Pressure or Stress
N	newtons	02.225	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)