Table 4-3 Performance Measurements for Selected Corridors on Weekdays: 2014
| Corridor | Average Speed | Peak Period Average Speed | Non-Peak Period Average Speed | Non-Peak/ Peak Ratio | Buffer Index |
|---|---|---|---|---|---|
| I-5: Medford, OR to Seattle, WA | 55.90 | 54.79 | 56.53 | 1.03 | 34.32 |
| I-5/CA 99: Sacramento, CA to Los Angeles, CA | 56.19 | 55.89 | 56.39 | 1.01 | 26.23 |
| I-10: Los Angeles, CA to Tucson, AZ | 59.44 | 58.53 | 59.85 | 1.02 | 24.02 |
| I-10: San Antonio, TX to New Orleans, LA | 61.67 | 60.78 | 62.18 | 1.02 | 24.98 |
| I-10: Pensacola, FL to I-75 (FL) | 64.02 | 64.02 | 64.03 | 1.00 | 5.39 |
| I-30: Little Rock, AR to Dallas, TX | 62.60 | 62.20 | 62.81 | 1.01 | 12.57 |
| I-35: Laredo, TX to Oklahoma City, OK | 60.72 | 59.72 | 61.21 | 1.02 | 22.81 |
| I-40: Oklahoma City, OK to Flagstaff, NM | 64.36 | 64.27 | 64.40 | 1.00 | 9.58 |
| I-40: Knoxville, TN to Little Rock, AR | 61.78 | 61.58 | 61.91 | 1.01 | 18.76 |
| I-40: Raleigh, NC to Asheville, NC | 62.02 | 61.56 | 62.24 | 1.01 | 11.36 |
| I-55/I-39/I-94: Saint Louis, MO to Minneapolis, MN | 62.35 | 62.16 | 62.48 | 1.01 | 10.74 |
| I-57/I-74: I-24 (IL) to I-55 (IL) | 62.92 | 62.92 | 62.92 | 1.00 | 10.97 |
| I-70: Kansas City, KS to Columbus, OH | 61.77 | 61.51 | 61.91 | 1.01 | 15.96 |
| I-65/I-24: Chattanooga, TN to Nashville, TN to Chicago, IL | 60.05 | 59.45 | 60.37 | 1.02 | 28.15 |
| I-75: Tampa, FL to Knoxville, TN | 62.25 | 61.70 | 62.58 | 1.01 | 16.23 |
| I-75: Lexington, KY to Detroit, MI | 59.82 | 59.30 | 60.15 | 1.01 | 24.56 |
| I-78/I-76: New York, NY to Pittsburgh, PA | 59.77 | 59.32 | 60.01 | 1.01 | 14.62 |
| I-80: New York, NY to Cleveland, OH | 61.10 | 60.71 | 61.30 | 1.01 | 15.80 |
| I-80: Cleveland, OH to Chicago, IL | 61.80 | 61.73 | 61.83 | 1.00 | 15.29 |
| I-80: Chicago, IL to I-76 (CO/NE border) | 63.46 | 63.40 | 63.48 | 1.00 | 10.33 |
| I-81: Harrisburg, PA to I-40 (Knoxville, TN) | 62.60 | 62.58 | 62.62 | 1.00 | 9.19 |
| I-84: Boise, ID to I-86 (ID) | 62.62 | 62.35 | 62.72 | 1.01 | 12.33 |
| I-94: Chicago, IL to Detroit, MI | 59.27 | 58.88 | 59.56 | 1.01 | 11.35 |
| I-95: Miami, FL to I-26 (SC) | 62.35 | 61.76 | 62.69 | 1.02 | 18.52 |
| I-95: Richmond (VA) to New Haven (CT) | 53.90 | 51.88 | 55.06 | 1.06 | 63.89 |
NOTES: For this table, reliability is expressed as a Buffer Index. The Buffer Index represents the extra buffer time (minutes) that most drivers add to their average travel time when planning trips to ensure on-time arrival. This extra time is added to account for any unexpected delay. The buffer index is expressed as a percentage and its value increases as reliability gets worse. This formulation of the buffer index uses a 95th percentile travel time to represent a near-worst case travel time. It represents the extra time a traveler should allow to arrive on-time for 95 percent of all trips. A simple analogy is that a driver who uses a 95 percent reliability indicator would be late only one weekday per month. The reliability measure is most meaningful when applied to an actual trip or segment. As it is applied to entire corridors in this table, the reliability calculation is applied to segments and then averaged for the corridor. The Buffer Index derived is not so much an actual percent that one would apply to determine reliability at any point on the corridor. Instead, it should be used in this case as an overall indicator of performance. The non-peak period/peak period ratio is calculated by dividing average speed during the non-peak period by average speed during the peark period. Higher ratios indicate corridors where the non-peak period average speed exceeds peak period average speed.
SOURCE: U.S. Department of Transportation, Federal Highway Administration, Office of Freight Management and Operations, Freight Performance Measurement Program, special tabulation, 2015.