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2021 National List of Major Freight Highway Bottlenecks and Congested Corridors
Federal Highway Administration (FHWA) Freight Mobility Trends: Truck Hours of Delay

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The following table lists the top Interstate bottlenecks and congested corridors in the U.S. based upon Annual Truck Hours of Delay per Mile from 2021. The U.S. Federal Highway Administration (FHWA) used the Freight Mobility Trends (FMT) tool with data from the National Performance Management Research Data Set (NPMRDS) (https://npmrds.ritis.org) to develop the list.

Annual Truck Hours of Delay per Mile is calculated for each Interstate segment using the 2021 NPMRDS travel time data as follows:

  • Delay is calculated for each 15-minute time period as the difference between actual travel time and reference travel time. Reference travel time is based on 85th percentile speed during off-peak and overnight time periods.
  • Delay for each 15-minute time period is multiplied by 15-minute truck volumes. Truck volumes are estimated from Annual Average Daily Truck Traffic (AADTT) using typical time-of-day traffic volume profiles. Delay for each 15-minute time period is aggregated to get Annual Truck Hours of Delay.
  • The total number of truck hours of delay is then divided by the segment length to get total truck hours of delay per mile, allowing for the comparison of all roadway sections across the National Highway System (NHS).

The above analysis has been conducted for 2017 through 2021 to compare trends in congestion and delay. The use of delay per mile for assessing bottlenecks is a consistent measure that allows for comparing performance over the entire Interstate system from year to year and across all States. Annual Truck Hours of Delay are quantified along corridors, as opposed to individual points, to consider the full delay that a truck would experience driving along a congested corridor.

The segment data for Annual Truck Hours of Delay was used as a starting point and was validated against other data sources. The top bottleneck locations were compared with the bottlenecks identified by States in their State Freight Plan and 2018 and 2020 Transportation Performance Management Performance Reports. Finally, the FHWA Office of Operations’ Office of Freight Management and Operations coordinated the locations with the FHWA Division Offices and State departments of transportation (DOTs) for review and comment.

Table 1 lists the Route, Urban Area, and State ranked by 2021 Truck Hours of Delay per Mile.

  • Most congested bottleneck segment:  Annual truck hours of delay per mile is determined at the most congested segment of the corridor.  Delay will be lower along other segments of the corridor.  Information is provided for AADTT, Annual Truck Hours of Delay, Planning Time Index (PTI), Buffer Index (BI), Travel Time Index (TTI), and Travel Reliability Index (TRI) is provided for the most congested segment of the corridor.
  • Full congested corridor:  Limits of Congested Corridor, Corridor Length, and Total Corridor Congestion Cost is calculated for the full extent of delay along the congested corridor, which may include multiple bottleneck segments.

Table 1. National List of Major Freight Highway Bottlenecks and Congested Corridors
Based on Truck Hours of Delay per Mile, 2021 National Performance Management Research Data Set
2021
Rank
2020
Rank
Road
Urban Area, State
Limits of Congested
Corridor
Corridor Length
(Miles)
AADTT
(Trucks)
Delay
(Hours)
Delay/
Mile
Change
From
2020
Change
From
2019
PTI
BI
TTI
TRI
Total
Congestion Cost
of Full Corridor
($/year)

1

1

I-95/ I-295

New York-Newark, NY-NJ-CT

US-46 in NJ to I-278/I-678 in NY

12

26,626

2,182,899

340,120

86%

29%

11.98

271.4

3.86

2.11

$159,883,554

2

2

I-90/ I-94

Chicago, IL-IN

I-94N to I-55

10.5

16,052

1,140,838

123,947

79%

-12%

8.13

172.2

2.97

2.38

$63,058,035

3

27

I-71/ I-75

Cincinnati, OH-KY-IN

I-275 in KY to Western Hills in OH

9.2

21,302

543,489

109,555

286%

146%

5.44

130.6

2.25

1.41

$30,037,300

4

3

I-278

New York-Newark, NY-NJ-CT

I-95/I-678 to Grand Central Pkwy.; and
SR-27 Prospect Expy. to SR-29 Queens Blvd.

7.7

9.2

19,650

2,703,702

106,846

58%

21%

7.62

199.9

2.71

2.38

$149,451,493

5

23

I-80

San Francisco-Oakland, CA

US-101 to Bay Bridge;
And at I-580

10.7

15,758

717,622

105,254

254%

106%

8.09

215.6

2.5

1.78

$39,665,893

6

4

I-678

New York-Newark, NY-NJ-CT

I-495 to Belt Parkway; and
I-295/I-95 to south end Bronx-Whitestone Bridge

5.8
2.9

13,550

480,092

101,075

50%

1%

7.1

175.1

2.59

2.33

$26,538,634

7

15

I-10

Baton Rouge, LA

I-110 to SR-1

2.2

22,378

647,215

90,002

143%

56%

6.43

257.5

1.8

2.54

$35,771,085

8

31

I-80/ I-94

Chicago, IL-IN

I-294 to I-94

4.8

49,806

963,494

82,968

200%

28%

3.05

126.2

1.43

2.57

$53,248,838

9

-

I-69C

McAllen, TX

At I-2

2.7

17,046

236,951

78,304

133%

119%

4.45

136.8

1.83

2.05

$13,093,864

10

6

I-87

New York-Newark, NY-NJ-CT

I-278 to 230th Street

5.9

11,502

408,332

77,972

76%

20%

7.39

216.7

2.34

1.78

$22,570,472

11

5

I-495

New York-Newark, NY-NJ-CT

Little Neck Parkway to Queens Midtown Tunnel

14.3

20,124

1,597,202

76,833

66%

8%

5.69

177.6

2.13

1.82

$88,287,636

12

11

I-45

Houston, TX

US-90 to I-69

4.2

18,374

593,798

73,569

85%

-13%

4.73

131.5

2.02

1.63

$32,817,007

13

8

I-35

Waco, TX

At 5th Street

1.4

29,552

630,635

72,581

68%

13%

4.64

193.6

1.57

2.86

$34,852,255

14

35

I-710

Los Angeles-Long Beach-Anaheim, CA

Cesar Chavez Ave. to Atlantic Blvd.

3

17,386

378,710

70,329

176%

-18%

6.2

231.7

1.77

2.9

$20,931,647

15

10

I-10

Los Angeles-Long Beach-Anaheim, CA

20th Street to I-5;
And at I-605

15.3
6.0

16,674

1,385,645

68,351

66%

-21%

7.6

240.8

2.23

2.63

$76,583,680

16

7

I-75

Chattanooga, TN-GA

At I-24

1.6

23,078

102,909

66,083

50%

62%

4.39

150.8

1.71

1.53

$5,687,739

17

17

I-5

Los Angeles-Long Beach-Anaheim, CA

SR-134 Ventura Fwy. to I-605

19.8

16,674

1,320,114

63,774

85%

-7%

5.75

199.4

1.92

1.88

$72,966,141

18

16

I-290

Chicago, IL-IN

I-90/I-94 to I-294

13.5

14,894

617,075

62,566

79%

-34%

4.61

155.9

1.8

1.95

$34,107,314

19

9

I-35

Austin, TX

US 290 N to Ben White Blvd/SH 71

7.9

18,820

454,504

62,363

49%

-44%

5.97

190.9

2.05

1.73

$25,120,597

20

38

I-5

Seattle, WA

I-90 to 85th St; and
SR-18 to Port of Tacoma Rd

9.6
7.1

14,582

882,485

62,041

147%

-11%

5.74

216

1.99

2.54

$48,774,259

21

12

I-610

Houston, TX

I-69 to I-10 and
At I-45

4.1
2.1

15,452

379,358

61,566

60%

-41%

5.71

210

1.93

2.49

$20,967,423

22

24

I-75/ I-85

Atlanta, GA

I-20 to I-75/I-85 split

4.2

14,710

326,884

61,019

109%

-4%

5.93

166.4

2.22

1.82

$18,068,079

23

36

I-285

Atlanta, GA

East/ SR-400 to US-78; and
West/ I-20 to Northside Dr

11.7
11.2

23,710

1,203,300

59,712

137%

11%

3.71

139.1

1.55

2.39

$66,501,658

24

-

I-40/ I-55

Memphis, TN-MS-AR

Between I-40 and I-55 split exits 279 and 277 in AR

2.7

29,118

158,998

59,510

661%

2309%

5.22

231.5

1.56

4.64

$8,786,757

25

22

I-69/ US-59

Houston, TX

SR-527 to I 10

4.4

13,774

350,962

58,407

95%

-35%

7.07

251.2

2.1

2.32

$19,396,490

26

18

I-405

Los Angeles-Long Beach-Anaheim, CA

At SR-73 and
SR-2 Santa Monica Blvd to SR-42 Manchester Blvd

2.5
7.5

15,162

1,311,450

58,005

73%

-39%

5.89

207.1

1.94

2.7

$72,484,527

27

54

I-75

Cincinnati, OH-KY-IN

SR-562 to SR-126

3

23,338

246,864

56,959

219%

65%

4.11

141.8

1.52

2.27

$13,644,113

28

39

I-105

Los Angeles-Long Beach-Anaheim, CA

I-405 to Long Beach Blvd

13.7

16,674

767,698

55,564

122%

-14%

6.78

270.3

1.8

4.63

$42,429,278

29

-

I-55

Memphis, TN-MS-AR

I-40 and I-55 split in AR to Crump Blvd on TN side of Mississippi River

4.7

21,294

144,247

54,996

1555%

1709%

6.61

323.4

1.55

5.85

$7,972,033

30

70

I-15

Las Vegas-Henderson, NV

I-515 to Tropicana Ave

5.5

31,010

634,588

54,634

258%

147%

3.09

118.6

1.41

1.96

$35,068,519

31

14

I-24

Nashville-Davidson, TN

US-41 to SR-155

5.8

26,772

474,415

53,456

42%

-38%

3.74

171.5

1.49

3.05

$26,221,736

32

13

I-35W

Dallas-Fort Worth-Arlington, TX

At I-30

1.2

13,818

97,911

52,554

38%

111%

4.62

121.3

2.06

1.3

$5,411,445

33

73

I-93

Boston, MA-NH-RI

At I-90; and
At SR-3

5.0
5.5

13,704

543,540

49,510

233%

81%

5.22

176.9

1.88

2.94

$30,042,839

34

29

I-24/ I-65

Nashville-Davidson, TN

I-65 to I-24

1.8

27,488

84,780

48,337

75%

50%

2.88

98.1

1.43

1.31

$4,685,762

35

20

I-95

Washington, DC-VA-MD

SR-123 to SR-286

6.3

17,652

595,518

46,146

41%

-6%

3.93

145

1.61

2.03

$32,912,098

36

53

I-80/ I-294

Chicago, IL-IN

I-94 to I-294

6.5

37,032

300,763

46,132

145%

40%

3.05

126.4

1.34

2.65

$16,622,028

37

64

I-10

Houston, TX

I-69 to I-45

2.1

19,098

291,811

44,603

176%

-75%

3.98

144.6

1.58

1.78

$16,128,461

38

26

I-25

Denver-Aurora, CO

I-70 to University Blvd

8.7

24,402

350,753

43,161

52%

-23%

4.16

152

1.65

2.47

$19,386,789

39

52

I-24

Chattanooga, TN-GA

I-75 to US-41

3.5

39,326

610,877

42,780

125%

33%

3.95

186.6

1.38

3.58

$33,763,659

40

44

I-75

Atlanta, GA

I-85 to Moores Mill Rd

3.3

16,804

261,395

42,285

95%

78%

4.85

208.3

1.57

2.5

$14,445,832

41

34

I-76

Philadelphia, PA-NJ-DE-MD

University Ave to US-1

6.2

11,440

305,582

42,017

62%

-37%

5.39

188.5

1.84

2.06

$16,891,818

42

21

I-270

Denver-Aurora, CO

I-25 to I-70

5.8

10,750

182,009

40,436

32%

-19%

5.85

191.9

1.98

1.86

$10,059,745

43

32

I-5

Portland, OR-WA

Columbia River to Terwilliger Blvd

10.5

19,440

503,062

40,407

48%

-27%

4.71

202.4

1.55

2.75

$27,804,513

44

49

I-10

New Orleans, LA

SR-49 to I-610 to and at Pontchartrain Expy.

7.5
3.9

39,384

412,570

39,944

102%

-35%

4.3

153.1

1.7

2.23

$22,800,365

45

45

I-55

Chicago, IL-IN

I-94 to SR-171

10

14,356

363,710

38,433

78%

-29%

4.89

181.9

1.69

2.22

$20,102,458

46

-

I-345/ US-75

Dallas-Fort Worth-Arlington, TX

Woodall Rodgers Fwy to   I-30

2

13,210

73,033

37,216

34%

5%

5.24

216.6

1.63

3.03

$4,036,493

47

19

I-30

Little Rock, AR

I-630 to I-40

2.9

40,520

334,023

36,188

9%

-30%

1.98

56

1.21

1.74

$18,461,092

48

48

I-95

Philadelphia, PA-NJ-DE-MD

At I-676

1.7

26,644

60,526

35,778

77%

0%

3.42

157.8

1.33

3.07

$3,345,131

49

47

I-635

Dallas-Fort Worth-Arlington, TX

I-35 to SR-78

14

18,302

624,526

35,693

73%

-4%

3.8

137

1.6

2.1

$34,515,016

50

40

I-676

Philadelphia, PA-NJ-DE-MD

I-76 to I-95

2.2

8,760

135,423

35,595

47%

-12%

4.69

142.4

2.03

1.64

$7,485,968

51

-

I-610

New Orleans, LA

At I-10

1.4

14,920

50,400

35,067

59%

-7%

4.8

220.4

1.49

3.65

$2,785,692

52

-

I-515

Las Vegas-Henderson, NV

I-15 to Flamingo Rd

7.1

18,342

281,575

34,631

367%

171%

4.3

132.6

1.79

1.56

$15,561,856

53

63

I-15

Los Angeles-Long Beach-Anaheim, CA

At I-10

3.2

16,674

174,824

34,480

106%

-28%

3.07

114.1

1.42

2

$9,662,995

54

30

I-70

Denver-Aurora, CO

I-25 to I-270

4.8

16,580

144,385

34,127

23%

-36%

3.97

141.9

1.64

1.79

$7,980,896

55

71

I-294

Chicago, IL-IN

At I-290; and
At I-90

6.1
3.9

31,888

351,488

33,250

118%

-21%

3.06

131.9

1.31

2.39

$19,426,409

56

28

I-30

Dallas-Fort Worth-Arlington, TX

I-35 to Grand Ave.

4

15,156

297,056

33,199

20%

6%

4.28

157.2

1.65

1.94

$16,418,607

57

33

I-95

Bridgeport-Stamford, CT-NY

At US-1 in Fairfield; and
At US-1 in Stamford

1.5
1.8

20,496

1,116,502

32,554

22%

19%

3.48

139.3

1.46

2.22

$61,708,615

58

55

I-95

New Haven, CT

I-91 to SR-10

1.8

15,794

58,948

32,277

82%

20%

3.92

172.6

1.43

2.98

$3,258,121

59

61

I-15

Riverside-San Bernardino, CA

At SR-91

2.2

11,350

113,529

32,247

92%

-33%

6.66

245.2

2.05

3.73

$6,274,869

60

I-15

Ogden-Layton, UT

I-84 to 650 N

4

24,584

172,848

32,081

101%

33%

3.38

155.6

1.32

2.85

$9,552,901

61

86

I-90

Chicago, IL-IN

I-90/94 to I-294

6.7

22,800

352,554

31,695

166%

-27%

6.29

160.3

2.42

2.5

$19,483,539

62

65

I-110

Los Angeles-Long Beach-Anaheim, CA

I-10 to SR-42 Stauson Ave.

3.4

11,556

96,545

31,370

94%

-36%

4.86

158.3

1.86

2.04

$5,336,276

63

90

I-64

St. Louis, MO-IL

Market St to I-70 (over Mississippi River)

5

10,130

41,181

30,634

170%

-28%

3.47

129.8

1.42

2.94

$2,275,952

64

58

I-880

San Francisco-Oakland, CA

SR-92 to SR-84

6.4

16,524

268,839

30,103

75%

-9%

3.02

109.3

1.43

1.62

$14,858,141

65

I-45

Dallas-Fort Worth-Arlington, TX

Illinois Ave to Wright Fwy

3.4

16,680

101,570

29,874

206%

89%

2.93

89.6

1.42

1.47

$5,613,271

66

51

I-695

Baltimore, MD

I-95 to I-795

10.1

19,174

31,097

29,491

53%

-36%

2.73

110.4

1.3

2.11

$1,718,878

67

46

I-605

Los Angeles-Long Beach-Anaheim, CA

I-5 to SR-60

6.5

16,024

179,208

29,179

38%

-79%

3.27

94.4

1.68

1.43

$9,905,503

68

69

I-215

Riverside-San Bernardino, CA

I-10 to SR-80

5.9

14,384

435,697

28,811

88%

-18%

2.92

79.5

1.54

1.28

$24,083,078

69

41

I-35E

Dallas-Fort Worth-Arlington, TX

I-30 to John W. Carpenter/SH 183

2.8

17,298

117,682

28,780

23%

-23%

3.02

111.3

1.42

1.69

$6,505,010

70

68

I-210

Los Angeles-Long Beach-Anaheim, CA

SR-39/164 Azusa Ave to SR-19 Rosemead Blvd

10

19,966

255,762

28,244

80%

-53%

2.87

116.3

1.36

1.8

$14,136,524

71

74

I-580

Concord, CA

At I-680

1.1

16,674

30,924

28,133

96%

-42%

3.66

166.8

1.37

3.01

$1,709,154

72

43

I-94

Chicago, IL-IN

I-90/94 to US-14

2.3

16,000

91,783

27,301

23%

-19%

3.03

117.7

1.39

1.63

$5,072,824

73

50

I-405

Seattle, WA

I-90 to SR-520

3.7

10,364

121,276

27,213

40%

-33%

4.35

171.6

1.56

2.27

$6,702,947

74

62

I-85

Atlanta, GA

I-75 to SR 13/141; and
I-285 to SR-378

2.8
6.6

23,884

322,228

27,192

63%

-28%

5.32

169.4

1.96

1.8

$17,807,833

75

79

I-580

San Francisco-Oakland, CA

At I-980 and
At US-101

1.4

16,674

37,888

26,717

106%

-31%

3.07

100.5

1.47

1.6

$2,093,729

76

80

I-10

Riverside-San Bernardino, CA

At I-215

8.5

20,308

223,143

26,329

345%

-16%

2.35

80.4

1.27

1.64

$12,333,853

77

66

I-24/ I-40

Nashville-Davidson, TN

I-24 to I-65

3.0

12,032

42,086

25,217

57%

-26%

3.11

111.9

1.46

1.48

$2,326,247

78

79

I-40

Memphis, TN-MS-AR

At I-55

2.8

19,464

71,443

24,961

95%

911%

1.9

33.2

1.4

1.77

$3,948,148

79

 

I-70

Rural, IN

SR-9 to N 600 W

9.6

18,104

231,819

24,229

608%

276%

3.51

138

1.46

1.61

$12,813,635

80

98

I-20

Dallas-Fort Worth-Arlington, TX

At SR-360

5.8

26,572

139,885

24,095

123%

106%

1.97

56.6

1.22

1.39

$7,730,484

81

88

I-40

Knoxville, TN

At I-140

2.3

20,680

54,804

24,063

108%

20%

2.64

108.7

1.25

2.24

$3,028,903

82

-

I-110

El Paso, TX-NM

I-10 to Mexican boarder

0.7

2,168

16,422

23,785

166%

379%

11.22

130.8

4.8

1.24

$907,489

83

-

I-205

Rural, CA

At I-580

4.0

13,870

89,660

23,343

31%

-43%

4.24

197

1.43

3.04

$4,955,402

84

-

I-630

Little Rock, AR

At I-30

0.7

33,186

15,886

23,312

127%

-3%

1.8

46.6

1.22

1.37

$877,947

85

37

I-495

Washington, DC-VA-MD

I-66 (VA) to I-95 (MD)

19.5

8644

83,856

23,167

264%

72%

2.39

90

1.25

1.84

$5,515,292

86

-

I-74/ I-465

Indianapolis, IN

I-65 to SR-37

4.3

20,244

99,783

23,167

264%

72%

2.39

89.9

1.25

1.84

$5,515,292

87

75

I-12

Baton Rouge, LA

At I-10

3.1

19,292

72,240

23,108

62%

-2%

2.07

65.9

1.24

1.88

$3,992,476

88

59

I-10

Lake Charles, LA

At I-210

9.3

29,982

208,203

22,434

31%

-63%

1.57

32.8

1.17

1.4

$11,506,626

89

77

I-20

Atlanta, GA

I-285 to SR-6

6.0

11,800

133,215

22,379

73%

16%

2.98

108.7

1.43

1.69

$7,363,013

90

78

I-820

Dallas-Fort Worth-Arlington, TX

At I-35W

3.0

8,596

66,133

22,237

72%

379%

3.61

98.5

1.68

1.37

$3,655,498

91

76

I-376

Pittsburgh, PA

Fort Pitt Bridge to Squirrel Hill

4.5

5,156

35,777

22,195

58%

-29%

5.19

211.7

1.67

2.7

$1,977,539

92

60

I-95

Aberdeen-Bel Air South-Bel Air North, MD

SR 24 to SR 152

1.6

23,414

35,629

21,597

28%

-40%

2.76

117.5

1.27

2.31

$1,969,047

93

-

I-55

St. Louis, MO-IL

I-44 and I-64

1.5

17,276

33,118

21,408

264%

83%

2.72

106.6

1.29

2.09

$1,830,424

94

-

I-287

New York-Newark, NY-NJ-CT

I-87 to SR-100

2.5

20,914

52,564

21,385

90%

-32%

2.03

62.5

1.23

1.26

$2,905,230

95

-

I-35

San Antonio, TX

At I-10

4.4

24,856

92,582

21,195

111%

-46%

2.22

79.6

1.22

1.6

$5,116,612

96

-

I-65

Nashville, TN

At SR-386

2.6

13,768

53,488

20,874

84%

4%

3.44

156

1.33

2.75

$2,955,977

97

-

I-5

San Diego, CA

Via de la Valle to Encinitas Blvd

5.2

16,674

105,443

20,351

 

 

2.69

108

1.29

2.05

$31,211,000

98

-

I-4

Tampa, FL

East of I-275

5.8

13,750

110,354

19,103

68%

-12%

1.36

61

2.32

1.32

$16,630,000

99

-

I-95

Miami, FL

Florida Turnpike to I-395

7.7

4,816

147,218

19,018

72%

-13%

3.90

146

1.58

2.00

$8,136,264

100

-

I-94

Milwaukee, WI

At I-41/I-894

2.9

7,004

43,760

15,219

75%

-19%

2.6

102

1.27

2.03

$2,418,631

AADTT = average daily truck traffic; BI = buffer index; PTI = planning time index; TRI = travel reliability index; TTI = travel time index.

Information is provided in the table for the overall congested corridor, the bottleneck segment with the greatest delay, and congestion costs for all congested segments with the urbanized area.

  • Limits of Congested Corridor and Corridor Length: Extent of congestion the primary bottleneck on the corridor, estimated based upon review of corridor congestion scans in the NPMRDS and review of State Freight Plans. For major congested corridors, this may include multiple contiguous bottlenecks. For corridors with multiple distinct bottleneck locations, two corridors will be noted. These locations have been further refined based upon review of 2021 NPMRDS data and State 2020 Performance Reports.
  • Bottleneck Segment with Greatest Delay: The following information is provided for the segment along the corridor with the greatest truck hours of delay per mile:
    • AADTT (Trucks): NPMRDS total single unit and combination trucks conflated from Highway Performance Monitoring System (HPMS). Note, the prior year HPMS data is conflated to the NPMRDS at the beginning of each year. Therefore the 2021 NPMRDS shows traffic counts that were taken in 2018.
    • Delay per Mile: Annual Truck Hours of Delay determined as the difference between actual travel time and reference travel time (“free-flow” travel time), multiplied by truck volumes for the segment with the greatest delay. Annual Truck Hours of Delay is divided by the segment length to provide the Delay per Mile. For larger bottlenecks that span multiple roadway segments, delay is provided for the most congested segment and direction of the bottleneck, not the full corridor.
    • Change from 2020: The percent change in Annual Truck Hours of Delay per Mile from 2020 to 2021.
    • Change from 2019: The percent change in Annual Truck Hours of Delay per Mile from 2019 to 2021 is provided for a comparison to pre-pandemic traffic conditions.
    • PTI: Ratio of the 95th percentile travel time to the reference travel time (“free-flow” travel time), computed during the AM and PM peak periods.
    • BI: Represents the extra time (or time cushion) that travelers must add to their average travel time when planning trips to ensure on-time arrival.
    • TTI: Ratio of the peak-period travel time to the reference travel time (“free-flow” travel time), computed for the AM and PM peak periods.
    • TRI: Ratio of the 95th percentile travel time to the 50th percentile travel time during five different time periods of the day. Calculated similar to the MAP-21 performance measure for Truck Travel Time Reliability (TTTR), however, results will differ from the NPMRDS TTTR due to differences in route segmentation.
  • Total Congestion Cost of Full Corridor ($/year): Calculated for the full extent of delay along the congested corridor as a function of both the time and fuel used while the truck is in congested traffic, factoring costs of personnel, commercial vehicle operation, and wasted fuel. For major bottlenecks with long congestion queues, this will include multiple roadway segments. For major congested corridors, the congestion cost will include the full cost of congestion along the corridor through the entire urban area, which may include multiple bottlenecks. This may include delay at other congested segments beyond the primary bottleneck in the urban area.

Changes Between 2020 and 2021

There was an overall increase in delay for nearly all bottlenecks as traffic volumes began to resume after the 2020 COVID-19 global pandemic stay at home orders.  Nationwide, there was a reduction in total truck delay on the Interstate system of 41 percent between 2019 and 2020 followed by an increase in 2021.  Total truck delay on the Interstate system in 2021 returned to 84 percent of 2019 pre-pandemic delay.

While there was a large increase in delay for nearly all bottlenecks, the following bottlenecks saw the greatest relative percent increase in delay between 2020 and 2021.  Major roadwork was another source of increased delay on certain routes.  As can be seen in Table 2, the emergency closure of the I-40 Hernando DeSoto Bridge over the Mississippi River caused largest increase in delay on I-55 and other roadways in the Memphis, TN-AR area.

Table 2. Greatest Increase in Delay Between 2020 and 2021
Road
Urban Area, State
Percent Increase in Delay
Per Mile From 2020
I–55 Memphis, TN-MS-AR
1555%
I–40/ I–55 Memphis, TN-MS-AR
661%
I–70 Rural, IN
608%
I–515 Las Vegas-Henderson, NV
367%
I–580 San Francisco-Oakland, CA
363%
I–71/ I–75 Cincinnati, OH-KY-IN
286%
I–74/ I–465 Indianapolis, IN
264%
I–55 St. Louis, MO-IL
264%
I–15 Las Vegas-Henderson, NV
258%
I–80 San Francisco-Oakland, CA
254%

Based upon changes to truck hours of delay per mile, the following bottlenecks saw a relative increase in delay, moving the locations to the top 100 bottlenecks, or a relative decrease in delay, dropping the locations below the top 100 bottlenecks.

The following bottlenecks were added to the list in 2021:

Table 3. Locations Added to Top 100
Between 2020 and 2021
Road
Urban Area, State
I–55 Memphis, TN-MS-AR
I–40/ I–55 Memphis, TN-MS-AR
I–70 Rural, IN
I–515 Las Vegas-Henderson, NV
I–74/ I–465 Indianapolis, IN
I–55 St. Louis, MO-IL
I–45 Dallas-Fort Worth-Arlington, TX
I–110 El Paso, TX-NM
I–69C McAllen, TX
I–630 Little Rock, AR
I–35 San Antonio, TX
I–15 Ogden-Layton, UT
I–287 New York-Newark, NY-NJ-CT
I–610 New Orleans, LA
I–345/ US-75 Dallas-Fort Worth-Arlington, TX
I–205 Rural, CA
I–5 San Diego, CA
I–4 Tampa-St. Petersburg, FL
I–94 Milwaukee, WI

 

The following bottlenecks from 2020 dropped off the list in 2021:

Table 4 Locations Removed From Top 100
Between 2020 and 2021
Road Urban Area, State
I–680 San Francisco-Oakland, CA
I–580 Livermore, CA
I–435 Kansas City, MO-KS
I–15 Salt Lake City, UT
I–95 Washington, DC-MD-VA
I–78 New York-Newark, NY-NJ
I–84 Waterbury, CT
I–39 Rockford IL
I–70 St. Louis, MO
I–270 St. Louis, MO
I–4 Orlando, FL
I–270 Washington, DC-MD-VA
I–225 Denver-Aurora, CO
I–95 Fredericksburg, VA
I–295 New York-Newark, NY-NJ-CT
I–80/ Chicago, IL-IN
I–35 Kansas City, MO-KS
I–15 Murrieta-Temecula-Menifee, CA
I–75 Toledo, OH

 

Mapped Locations

The following map shows the top Interstate bottlenecks in the U.S. as listed in table 1 based on Annual Truck Hours of Delay per Mile for 2021

 

Map showing the location of the 2021 top 100 major Interstate freight bottlenecks ranked by Truck Hours of Delay per Mile as listed in table 1

Map 1. Major Interstate Highway Freight Bottlenecks Based on Annual Truck Hours of Delay per Mile, 2021 NPMRDS

MapMap showing the location of the 2021 top 100 major Interstate freight bottlenecks ranked by Truck Hours of Delay per Mile as listed in table 1: I-95/ I-295 New York-Newark, NY-NJ-CT, I-90/ I-94 Chicago, IL-IN, I-71/ I-75 Cincinnati, OH-KY-IN, I-278 New York-Newark, NY-NJ-CT, I-80 San Francisco-Oakland, CA, I-678 New York-Newark, NY-NJ-CT, I-10 Baton Rouge, LA, I-80/ I-94 Chicago, IL-IN, I-69C McAllen, TX, I-87 New York-Newark, NY-NJ-CT, I-495 New York-Newark, NY-NJ-CT, I-45 Houston, TX, I-35 Waco, TX, I-710 Los Angeles-Long Beach-Anaheim, CA, I-10 Los Angeles-Long Beach-Anaheim, CA, I-75 Chattanooga, TN-GA, I-5 Los Angeles-Long Beach-Anaheim, CA, I-290 Chicago, IL-IN, I-35 Austin, TX, I-5 Seattle, WA, I-610 Houston, TX, I-75/ I-85 Atlanta, GA, I-285 Atlanta, GA, I-40/ I-55 Memphis, TN-MS-AR, I-69/ US-59 Houston, TX, I-405 Los Angeles-Long Beach-Anaheim, CA, I-75 Cincinnati, OH-KY-IN, I-105 Los Angeles-Long Beach-Anaheim, CA, I-55 Memphis, TN-MS-AR, I-15 Las Vegas-Henderson, NV, I-24 Nashville-Davidson, TN, I-35W Dallas-Fort Worth-Arlington, TX, I-93 Boston, MA-NH-RI, I-24/ I-65 Nashville-Davidson, TN, I-95 Washington, DC-VA-MD, I-80/ I-294 Chicago, IL-IN, I-10 Houston, TX, I-25 Denver-Aurora, CO, I-24 Chattanooga, TN-GA, I-75 Atlanta, GA, I-76 Philadelphia, PA-NJ-DE-MD, I-270 Denver-Aurora, CO, I-5 Portland, OR-WA, I-10 New Orleans, LA, I-55 Chicago, IL-IN, I-345/ US-75 Dallas-Fort Worth-Arlington, TX, I-30 Little Rock, AR, I-95 Philadelphia, PA-NJ-DE-MD, I-635 Dallas-Fort Worth-Arlington, TX, I-676 Philadelphia, PA-NJ-DE-MD, I-610 New Orleans, LA, I-515 Las Vegas-Henderson, NV, I-15 Los Angeles-Long Beach-Anaheim, CA, I-70 Denver-Aurora, CO, I-294 Chicago, IL-IN, I-30 Dallas-Fort Worth-Arlington, TX, I-95 Bridgeport-Stamford, CT-NY, I-95 New Haven, CT, I-15 Riverside-San Bernardino, CA, I-15 Ogden-Layton, UT, I-90 Chicago, IL-IN, I-110 Los Angeles-Long Beach-Anaheim, CA, I-64 St. Louis, MO-IL, I-880 San Francisco-Oakland, CA, I-45 Dallas-Fort Worth-Arlington, TX, I-695 Baltimore, MD, I-605 Los Angeles-Long Beach-Anaheim, CA, I-215 Riverside-San Bernardino, CA, I-35E Dallas-Fort Worth-Arlington, TX, I-210 Los Angeles-Long Beach-Anaheim, CA, I-580 Concord, CA, I-94 Chicago, IL-IN, I-405 Seattle, WA, I-85 Atlanta, GA, I-580 San Francisco-Oakland, CA, I-10 Riverside-San Bernardino, CA, I-24/ I-40 Nashville-Davidson, TN, I-40 Memphis, TN-MS-AR, I-70 Rural, IN, I-20 Dallas-Fort Worth-Arlington, TX, I-40 Knoxville, TN, I-110 El Paso, TX-NM, I-205 Rural, CA, I-630 Little Rock, AR, I-495 Washington, DC-VA-MD, I-74/ I-465 Indianapolis, IN, I-12 Baton Rouge, LA, I-10 Lake Charles, LA, I-20 Atlanta, GA, I-820 Dallas-Fort Worth-Arlington, TX, I-376 Pittsburgh, PA, I-95 Aberdeen-Bel Air South-Bel Air North, MD, I-55 St. Louis, MO-IL, I-287 New York-Newark, NY-NJ-CT, I-35 San Antonio, TX, I-65 Nashville, TN, I-5 San Diego, CA, I-4 Tampa, FL, I-95 Miami, FL, I-94 Milwaukee, WI.

Description automatically generated with medium confidence.

Other Bottlenecks

The analysis in this report uses delay per mile for assessing bottlenecks to allow for comparison over the entire Interstate system across all States. Individual State DOTs and Metropolitan Planning Organizations (MPOs) use a range of bottleneck identification methods based upon their freight plan development process and local traffic characteristics, infrastructure constraints, and impediments to efficient freight movement.

There is a range of methods for measuring congestion, delay, and reliability. Reliability is another factor that is important to the freight industry and can be measured with metrics such as the Truck Travel Time Reliability national performance measure or some of the other indices listed in Table 1.

In addition to congestion-based delay, some truck freight bottlenecks can be attributed to infrastructure restrictions that uniquely impact trucks, such as bridges with weight or clearance restrictions; steep grades; frequent adverse weather; or constraints at facilities, such as ports, intermodal rail facilities, and border crossings.

Individual State Freight Plans should be reviewed for additional information on the various types of freight bottlenecks.
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