Evaluation of Travel Time Methods to Support Mobility Performance Monitoring:
Blue Water Bridge (Page 3 of 3)
Freight Delay Analysis
The measure for the freight transportation system at international roadway border crossings is travel delay per truck trip through the first inspection point in the import country. Delay is measured relative to the travel time at low volume conditions, which will allow the processing time of the inspection to be accommodated outside of the measure. Estimating the average delay per truck for each hour where congestion is present and then applying the average hourly truck volume produces an estimate of total delay.
The average delay per truck for each hour is the difference between the travel time at low volume conditions and the travel time each hour. Travel time is also affected by the number of open inspection booths and this information was recorded on all days as it changed. To determine the average travel time for each road segment, the matched license plate data in the database is used. The number of matches are noted for statistical analysis and the travel time is noted for each hour. The travel time for each truck was assigned to the hour when they passed through the primary customs inspection location as this was the only location that remained consistent throughout the data collection. It should be noted, however, that the hourly volumes are obtained from the bridge operators and are measured at the toll booths.
The data are presented in Tables 8 through 19. The columns illustrate the key elements for estimating delay:
- No Delay Travel Time – The time through the system at low volume conditions. For this report, the value used was that of the lowest hourly travel time in that direction for each three-day data collection period.
- Average Number of Open Booths – The average number of primary Customs commercial vehicle inspection booths open and available for processing trucks. This figure is not used to compute delay but is useful to help understand the relationship between booths, traffic volume, and delay.
- Number of Matched Vehicles – The number of vehicle observation used to estimate the travel time for each hour.
- Average Travel Time – The amount of travel time from entry to exit for trucks entering the system each hour (use the time the vehicle passes the advance point as the determinant of the time period label).
- Delay per Trip – The difference between the average travel time and the "no delay" time.
- Average Traffic Volume – The average hourly truck volume for the "season" or time of year being analyzed.
- Total Delay – The product of the hourly truck volume and delay per trip.
| Time Period | (a) "No Delay" Travel Time |
(b) Average No. of Open Booths |
(c) Number of "Matched" Vehicles |
(d) Average Travel Time |
(e) Delay Per Trip (d - a) |
(f) Average Traffic Volume |
(g) Total Delay (f x e) |
|---|---|---|---|---|---|---|---|
| 6:00–7:00 AM | 4.80 | 2.12 | 41 | 5.40 | 0.60 | 72.00 | 43.20 |
| 7:00–8:00 AM | 4.80 | 2.15 | 52 | 5.20 | 0.40 | 95.75 | 38.30 |
| 8:00–9:00 AM | 4.80 | 4.00 | 94 | 5.82 | 1.02 | 135.25 | 137.50 |
| 9:00–10:00 AM | 4.80 | 4.00 | 114 | 5.18 | 0.38 | 143.75 | 55.10 |
| 10:00–11:00 AM | 4.80 | 4.00 | 96 | 5.45 | 0.65 | 153.25 | 99.61 |
| 11:00–12:00 PM | 4.80 | 4.00 | 111 | 5.77 | 0.97 | 157.75 | 152.49 |
| 12:00–1:00 PM | 4.80 | 4.05 | 98 | 5.42 | 0.62 | 155.75 | 96.05 |
| 1:00–2:00 PM | 4.80 | 4.00 | 111 | 6.83 | 2.03 | 155.25 | 315.68 |
| 2:00–3:00 PM | 4.80 | 4.00 | 112 | 5.98 | 1.18 | 158.50 | 187.56 |
| 3:00–4:00 PM | 4.80 | 4.00 | 100 | 5.38 | 0.58 | 162.75 | 94.94 |
| 4:00–5:00 PM | 4.80 | 4.00 | 116 | 5.57 | 0.77 | 152.50 | 116.92 |
| 5:00–6:00 PM | 4.80 | 4.00 | 101 | 4.98 | 0.18 | 155.75 | 28.55 |
| 6:00–7:00 PM | 4.80 | 2.95 | 51 | 5.08 | 0.28 | 153.75 | 43.56 |
| Time Period | (a) "No Delay" Travel Time |
(b) Average No. of Open Booths |
(c) Number of "Matched" Vehicles |
(d) Average Travel Time |
(e) Delay Per Trip (d - a) |
(f) Average Traffic Volume |
(g) Total Delay (f x e) |
|---|---|---|---|---|---|---|---|
| 9:00–10:00 AM | 4.80 | 4.00 | 75 | 6.20 | 1.40 | 143.75 | 201.25 |
| 10:00–11:00 AM | 4.80 | 4.00 | 130 | 7.22 | 2.42 | 153.25 | 370.35 |
| 11:00–12:00 PM | 4.80 | 4.00 | 132 | 7.22 | 2.42 | 157.75 | 381.23 |
| 12:00–1:00 PM | 4.80 | 4.00 | 91 | 9.95 | 5.15 | 155.75 | 802.11 |
| 1:00–2:00 PM | 4.80 | 4.00 | 133 | 9.08 | 4.28 | 155.25 | 664.99 |
| 2:00–3:00 PM | 4.80 | 4.00 | 137 | 9.22 | 4.42 | 158.50 | 700.04 |
| 3:00–4:00 PM | 4.80 | 4.00 | 123 | 6.57 | 1.77 | 162.75 | 287.53 |
| 4:00–5:00 PM | 4.80 | 4.00 | 110 | 4.80 | 0.00 | 152.50 | 0.00 |
| 5:00–6:00 PM | 4.80 | 4.00 | 126 | 5.60 | 0.80 | 155.75 | 124.60 |
| 6:00–7:00 PM | 4.80 | 4.00 | 127 | 5.75 | 0.95 | 153.75 | 146.06 |
| 7:00–8:00 PM | 4.80 | 3.66 | 121 | 5.63 | 0.83 | 145.00 | 120.83 |
| 8:00–9:00 PM | 4.80 | 3.00 | 102 | 10.02 | 5.22 | 137.00 | 714.68 |
| 9:00–10:00 PM | 4.80 | 3.00 | 47 | 14.62 | 9.82 | 126.75 | 1,244.26 |
| Time Period | (a) "No Delay" Travel Time |
(b) Average No. of Open Booths |
(c) Number of "Matched" Vehicles |
(d) Average Travel Time |
(e) Delay Per Trip (d - a) |
(f) Average Traffic Volume |
(g) Total Delay (f x e) |
|---|---|---|---|---|---|---|---|
| 9:00–10:00 AM | 4.80 | 4.00 | 101 | 6.63 | 1.83 | 143.75 | 263.54 |
| 10:00–11:00 AM | 4.80 | 4.00 | 114 | 5.25 | 0.45 | 153.25 | 68.96 |
| 11:00–12:00 PM | 4.80 | 4.00 | 111 | 6.88 | 2.08 | 157.75 | 328.65 |
| 12:00–1:00 PM | 4.80 | 4.00 | 131 | 6.00 | 1.20 | 155.75 | 186.90 |
| 1:00–2:00 PM | 4.80 | 4.00 | 147 | 5.93 | 1.13 | 155.25 | 175.95 |
| 2:00–3:00 PM | 4.80 | 4.00 | 148 | 5.17 | 0.37 | 158.50 | 58.12 |
| 3:00–4:00 PM | 4.80 | 4.00 | 117 | 6.37 | 1.57 | 162.75 | 254.98 |
| 4:00–5:00 PM | 4.80 | 4.00 | 121 | 5.10 | 0.30 | 152.50 | 45.75 |
| 5:00–6:00 PM | 4.80 | 4.00 | 126 | 5.47 | 0.67 | 155.75 | 103.83 |
| 6:00–7:00 PM | 4.80 | 4.00 | 101 | 5.47 | 0.67 | 153.75 | 102.50 |
| 7:00–8:00 PM | 4.80 | 3.71 | 117 | 6.87 | 2.07 | 145.00 | 299.67 |
| 8:00–9:00 PM | 4.80 | 3.84 | 115 | 8.62 | 3.82 | 137.00 | 522.88 |
| 9:00–10:00 PM | 4.80 | 4.00 | 30 | 5.55 | 0.75 | 126.75 | 95.06 |
| Time Period | (a) "No Delay" Travel Time |
(b) Average No. of Open Booths |
(c) Number of "Matched" Vehicles |
(d) Average Travel Time |
(e) Delay Per Trip (d - a) |
(f) Average Traffic Volume |
(g) Total Delay (f x e) |
|---|---|---|---|---|---|---|---|
| 6:00–7:00 AM | 4.98 | 2.00 | 38 | 5.03 | 0.05 | 69.75 | 3.49 |
| 7:00–8:00 AM | 4.98 | 2.12 | 61 | 6.68 | 1.70 | 92.25 | 156.83 |
| 8:00–9:00 AM | 4.98 | 4.00 | 97 | 5.13 | 0.15 | 129.25 | 19.39 |
| 9:00–10:00 AM | 4.98 | 4.00 | 65 | 5.33 | 0.35 | 137.50 | 48.13 |
| 10:00–11:00 AM | 4.98 | 4.00 | 80 | 5.18 | 0.20 | 155.00 | 31.00 |
| 11:00–12:00 PM | 4.98 | 4.00 | 80 | 5.68 | 0.70 | 155.00 | 108.50 |
| 12:00–1:00 PM | 4.98 | 4.00 | 77 | 6.02 | 1.03 | 152.50 | 157.58 |
| 1:00–2:00 PM | 4.98 | 4.00 | 102 | 5.65 | 0.67 | 156.00 | 104.00 |
| 2:00–3:00 PM | 4.98 | 4.00 | 109 | 4.98 | 0.00 | 153.25 | 0.00 |
| 3:00–4:00 PM | 4.98 | 4.00 | 107 | 5.28 | 0.30 | 158.75 | 47.63 |
| 4:00–5:00 PM | 4.98 | 4.00 | 102 | 5.17 | 0.18 | 157.25 | 28.83 |
| 5:00–6:00 PM | 4.98 | 4.00 | 83 | 5.00 | 0.02 | 147.50 | 2.46 |
| 6:00–7:00 PM | 4.98 | 4.00 | 36 | 5.07 | 0.08 | 146.25 | 12.19 |
| Time Period | (a) "No Delay" Travel Time |
(b) Average No. of Open Booths |
(c) Number of "Matched" Vehicles |
(d) Average Travel Time |
(e) Delay Per Trip (d - a) |
(f) Average Traffic Volume |
(g) Total Delay (f x e) |
|---|---|---|---|---|---|---|---|
| 9:00–10:00 AM | 4.98 | 4.00 | 34 | 5.68 | 0.70 | 137.50 | 96.25 |
| 10:00–11:00 AM | 4.98 | 4.00 | 96 | 5.45 | 0.47 | 155.00 | 72.33 |
| 11:00–12:00 PM | 4.98 | 4.00 | 102 | 5.43 | 0.45 | 155.00 | 69.75 |
| 12:00–1:00 PM | 4.98 | 4.00 | 111 | 5.67 | 0.68 | 152.50 | 104.21 |
| 1:00–2:00 PM | 4.98 | 4.00 | 120 | 7.23 | 2.25 | 156.00 | 351.00 |
| 2:00–3:00 PM | 4.98 | 4.00 | 130 | 6.70 | 1.72 | 153.25 | 263.08 |
| 3:00–4:00 PM | 4.98 | 4.00 | 136 | 6.15 | 1.17 | 158.75 | 185.21 |
| 4:00–5:00 PM | 4.98 | 4.00 | 118 | 5.47 | 0.48 | 157.25 | 76.00 |
| 5:00–6:00 PM | 4.98 | 4.00 | 107 | 5.28 | 0.30 | 147.50 | 44.25 |
| 6:00–7:00 PM | 4.98 | 4.00 | 92 | 5.43 | 0.45 | 146.25 | 65.81 |
| 7:00–8:00 PM | 4.98 | 4.00 | 100 | 5.55 | 0.57 | 143.25 | 81.18 |
| 8:00–9:00 PM | 4.98 | 3.93 | 76 | 7.62 | 2.63 | 141.00 | 371.30 |
| 9:00–10:00 PM | 4.98 | 3.99 | 32 | 8.28 | 3.30 | 123.75 | 408.38 |
| Time Period | (a) "No Delay" Travel Time |
(b) Average No. of Open Booths |
(c) Number of "Matched" Vehicles |
(d) Average Travel Time |
(e) Delay Per Trip (d - a) |
(f) Average Traffic Volume |
(g) Total Delay (f x e) |
|---|---|---|---|---|---|---|---|
| 9:00–10:00 AM | 4.98 | 4.00 | 71 | 5.57 | 0.58 | 137.50 | 80.21 |
| 10:00–11:00 AM | 4.98 | 4.00 | 98 | 5.93 | 0.95 | 155.00 | 147.25 |
| 11:00–12:00 PM | 4.98 | 4.00 | 119 | 7.47 | 2.48 | 155.00 | 384.92 |
| 12:00–1:00 PM | 4.98 | 4.00 | 106 | 6.47 | 1.48 | 152.50 | 226.21 |
| 1:00–2:00 PM | 4.98 | 4.00 | 106 | 6.70 | 1.72 | 156.00 | 267.80 |
| 2:00–3:00 PM | 4.98 | 4.00 | 110 | 5.55 | 0.57 | 153.25 | 86.84 |
| 3:00–4:00 PM | 4.98 | 4.00 | 119 | 5.50 | 0.52 | 158.75 | 82.02 |
| 4:00–5:00 PM | 4.98 | 4.00 | 132 | 6.07 | 1.08 | 157.25 | 170.35 |
| 5:00–6:00 PM | 4.98 | 4.00 | 114 | 5.87 | 0.88 | 147.50 | 130.29 |
| 6:00–7:00 PM | 4.98 | 4.00 | 84 | 5.67 | 0.68 | 146.25 | 99.94 |
| 7:00–8:00 PM | 4.98 | 4.00 | 117 | 8.47 | 3.48 | 143.25 | 498.99 |
| 8:00–9:00 PM | 4.98 | 4.00 | 67 | 6.13 | 1.15 | 141.00 | 162.15 |
| 9:00–10:00 PM | 4.98 | 4.00 | 33 | 5.78 | 0.80 | 123.75 | 99.00 |
| Time Period | (a) "No Delay" Travel Time |
(b) Average No. of Open Booths |
(c) Number of "Matched" Vehicles |
(d) Average Travel Time |
(e) Delay Per Trip (d - a) |
(f) Average Traffic Volume |
(g) Total Delay (f x e) |
|---|---|---|---|---|---|---|---|
| 6:00–7:00 AM | 8.67 | 2.76 | 24 | 30.57 | 21.90 | 133.71 | 2,927.84 |
| 7:00–8:00 AM | 8.67 | 3.00 | 109 | 34.53 | 25.86 | 136.67 | 3,534.82 |
| 8:00–9:00 AM | 8.67 | 3.00 | 140 | 27.35 | 18.68 | 144.79 | 2,704.65 |
| 9:00–10:00 AM | 8.67 | 3.00 | 110 | 23.42 | 14.75 | 152.06 | 2,242.34 |
| 10:00–11:00 AM | 8.67 | 3.00 | 114 | 24.32 | 15.65 | 150.52 | 2,355.12 |
| 11:00–12:00 PM | 8.67 | 3.00 | 86 | 32.38 | 23.71 | 141.06 | 3,344.95 |
| 12:00–1:00 PM | 8.67 | 3.00 | 123 | 36.30 | 27.63 | 137.08 | 3,787.44 |
| 1:00–2:00 PM | 8.67 | 3.00 | 98 | 38.22 | 29.55 | 153.54 | 4,536.55 |
| 2:00–3:00 PM | 8.67 | 3.00 | 113 | 43.75 | 35.08 | 153.87 | 5,397.60 |
| 3:00–4:00 PM | 8.67 | 3.80 | 25 | 41.03 | 32.36 | 152.50 | 4,935.41 |
| 4:00–5:00 PM | 8.67 | 4.00 | 128 | 28.93 | 20.26 | 157.06 | 3,182.51 |
| 5:00–6:00 PM | 8.67 | 3.92 | 79 | 20.02 | 11.35 | 157.69 | 1,789.28 |
| Time Period | (a) "No Delay" Travel Time |
(b) Average No. of Open Booths |
(c) Number of "Matched" Vehicles |
(d) Average Travel Time |
(e) Delay Per Trip (d - a) |
(f) Average Traffic Volume |
(g) Total Delay (f x e) |
|---|---|---|---|---|---|---|---|
| 9:00–10:00 AM | 8.67 | 3.00 | 74 | 18.10 | 9.43 | 152.06 | 1,433.90 |
| 10:00–11:00 AM | 8.67 | 3.00 | 121 | 18.67 | 10.00 | 150.52 | 1,504.69 |
| 11:00–12:00 PM | 8.67 | 3.00 | 82 | 30.32 | 21.65 | 141.06 | 3,053.43 |
| 12:00–1:00 PM | 8.67 | 3.00 | 122 | 39.78 | 31.11 | 137.08 | 4,264.92 |
| 1:00–2:00 PM | 8.67 | 3.75 | 173 | 30.07 | 21.40 | 153.54 | 3,285.21 |
| 2:00–3:00 PM | 8.67 | 3.83 | 122 | 14.42 | 5.75 | 153.87 | 884.21 |
| 3:00–4:00 PM | 8.67 | 3.00 | 120 | 17.48 | 8.81 | 152.50 | 1,344.03 |
| 4:00–5:00 PM | 8.67 | 2.89 | 138 | 23.18 | 14.51 | 157.06 | 2,279.43 |
| 5:00–6:00 PM | 8.67 | 3.00 | 150 | 21.38 | 12.71 | 157.69 | 2,004.79 |
| 6:00–7:00 PM | 8.67 | 3.00 | 131 | 17.37 | 8.70 | 145.44 | 1,264.86 |
| 7:00–8:00 PM | 8.67 | 3.00 | 141 | 18.95 | 10.28 | 136.56 | 1,403.81 |
| 8:00–9:00 PM | 8.67 | 3.00 | 108 | 14.87 | 6.20 | 125.12 | 775.30 |
| 9:00–10:00 PM | 8.67 | 3.00 | 50 | 18.68 | 10.01 | 125.81 | 1,259.75 |
| Time Period | (a) "No Delay" Travel Time |
(b) Average No. of Open Booths |
(c) Number of "Matched" Vehicles |
(d) Average Travel Time |
(e) Delay Per Trip (d - a) |
(f) Average Traffic Volume |
(g) Total Delay (f x e) |
|---|---|---|---|---|---|---|---|
| 9:00–10:00 AM | 8.67 | 3.45 | 76 | 27.17 | 18.50 | 152.06 | 2,812.56 |
| 10:00–11:00 AM | 8.67 | 3.00 | 162 | 28.85 | 20.18 | 150.52 | 3,037.48 |
| 11:00–12:00 PM | 8.67 | 3.00 | 127 | 15.55 | 6.88 | 141.06 | 970.48 |
| 12:00–1:00 PM | 8.67 | 3.00 | 103 | 16.22 | 7.55 | 137.08 | 1,034.47 |
| 1:00–2:00 PM | 8.67 | 3.00 | 138 | 17.82 | 9.15 | 153.54 | 1,404.37 |
| 2:00–3:00 PM | 8.67 | 3.00 | 106 | 18.82 | 10.15 | 153.87 | 1,561.22 |
| 3:00–4:00 PM | 8.67 | 2.95 | 109 | 18.30 | 9.63 | 152.50 | 1,468.58 |
| 4:00–5:00 PM | 8.67 | 2.09 | 99 | 25.63 | 16.96 | 157.06 | 2,664.22 |
| 5:00–6:00 PM | 8.67 | 3.00 | 133 | 36.90 | 28.23 | 157.69 | 4,451.65 |
| 6:00–7:00 PM | 8.67 | 3.00 | 100 | 19.77 | 11.10 | 145.44 | 1,613.92 |
| 7:00–8:00 PM | 8.67 | 3.00 | 124 | 12.32 | 3.65 | 136.56 | 497.98 |
| 8:00–9:00 PM | 8.67 | 3.00 | 98 | 8.67 | 0.00 | 125.12 | 0.00 |
| 9:00–10:00 PM | 8.67 | 2.00 | 43 | 14.68 | 6.02 | 125.81 | 756.94 |
| Time Period | (a) "No Delay" Travel Time |
(b) Average No. of Open Booths |
(c) Number of "Matched" Vehicles |
(d) Average Travel Time |
(e) Delay Per Trip (d - a) |
(f) Average Traffic Volume |
(g) Total Delay (f x e) |
|---|---|---|---|---|---|---|---|
| 7:00–8:00 AM | 15.05 | 3.00 | 15 | 58.08 | 43.03 | 138.76 | 5,971.27 |
| 8:00–9:00 AM | 15.05 | 3.00 | 55 | 60.15 | 45.10 | 146.26 | 6,596.29 |
| 9:00–10:00 AM | 15.05 | 2.93 | 57 | 57.05 | 42.00 | 142.81 | 5,998.22 |
| 10:00–11:00 AM | 15.05 | 3.00 | 71 | 57.62 | 42.57 | 142.83 | 6,079.94 |
| 11:00–12:00 PM | 15.05 | 3.00 | 55 | 63.75 | 48.70 | 146.56 | 7,137.26 |
| 12:00–1:00 PM | 15.05 | 3.00 | 78 | 72.65 | 57.60 | 139.04 | 8,008.53 |
| 1:00–2:00 PM | 15.05 | 3.00 | 12 | 75.13 | 60.08 | 148.24 | 8,906.80 |
| 2:00–3:00 PM | 15.05 | 3.00 | 72 | 80.63 | 65.58 | 156.89 | 10,289.30 |
| 3:00–4:00 PM | 15.05 | 3.00 | 55 | 90.73 | 75.68 | 148.56 | 11,243.18 |
| 4:00–5:00 PM | 15.05 | 3.00 | 65 | 83.90 | 68.85 | 152.37 | 10,490.70 |
| 5:00–6:00 PM | 15.05 | 2.99 | 67 | 80.10 | 65.05 | 155.20 | 10,096.00 |
| 6:00–7:00 PM | 15.05 | 3.00 | 50 | 83.92 | 68.87 | 145.57 | 10,025.20 |
| Time Period | (a) "No Delay" Travel Time |
(b) Average No. of Open Booths |
(c) Number of "Matched" Vehicles |
(d) Average Travel Time |
(e) Delay Per Trip (d - a) |
(f) Average Traffic Volume |
(g) Total Delay (f x e) |
|---|---|---|---|---|---|---|---|
| 10:00–11:00 AM | 15.05 | 3.00 | 32 | 62.32 | 47.27 | 142.83 | 6,751.26 |
| 11:00–12:00 PM | 15.05 | 3.94 | 125 | 51.25 | 36.20 | 146.56 | 5,305.31 |
| 12:00–1:00 PM | 15.05 | 3.98 | 110 | 36.33 | 21.28 | 139.04 | 2,959.17 |
| 1:00–2:00 PM | 15.05 | 4.00 | 92 | 29.12 | 14.07 | 148.24 | 2,085.25 |
| 2:00–3:00 PM | 15.05 | 3.41 | 95 | 40.55 | 25.50 | 156.89 | 4,000.67 |
| 3:00–4:00 PM | 15.05 | 3.00 | 121 | 37.50 | 22.45 | 148.56 | 3,335.07 |
| 4:00–5:00 PM | 15.05 | 3.00 | 127 | 30.53 | 15.48 | 152.37 | 2,359.20 |
| 5:00–6:00 PM | 15.05 | 3.00 | 131 | 26.10 | 11.05 | 155.20 | 1,715.00 |
| 6:00–7:00 PM | 15.05 | 2.69 | 126 | 16.75 | 1.70 | 145.57 | 247.48 |
| 7:00–8:00 PM | 15.05 | 2.38 | 114 | 19.97 | 4.92 | 139.48 | 685.78 |
| 8:00–9:00 PM | 15.05 | 2.08 | 92 | 23.47 | 8.42 | 125.93 | 1,059.88 |
| 9:00–10:00 PM | 15.05 | 2.92 | 55 | 30.67 | 15.62 | 133.07 | 2,078.17 |
| Time Period | (a) "No Delay" Travel Time |
(b) Average No. of Open Booths |
(c) Number of "Matched" Vehicles |
(d) Average Travel Time |
(e) Delay Per Trip (d - a) |
(f) Average Traffic Volume |
(g) Total Delay (f x e) |
|---|---|---|---|---|---|---|---|
| 9:00–10:00 AM | 15.05 | 3.00 | 2 | 21.40 | 6.35 | 142.81 | 906.87 |
| 10:00–11:00 AM | 15.05 | 3.00 | 75 | 55.40 | 40.35 | 142.83 | 5,763.33 |
| 11:00–12:00 PM | 15.05 | 3.00 | 110 | 49.53 | 34.48 | 146.56 | 5,053.72 |
| 12:00–1:00 PM | 15.05 | 3.00 | 87 | 41.52 | 26.47 | 139.04 | 3,679.85 |
| 1:00–2:00 PM | 15.05 | 3.00 | 122 | 33.23 | 18.18 | 148.24 | 2,695.51 |
| 2:00–3:00 PM | 15.05 | 3.00 | 93 | 26.13 | 11.08 | 156.89 | 1,738.85 |
| 3:00–4:00 PM | 15.05 | 3.12 | 96 | 23.48 | 8.43 | 148.56 | 1,252.82 |
| 4:00–5:00 PM | 15.05 | 3.68 | 122 | 17.18 | 2.13 | 152.37 | 325.06 |
| 5:00–6:00 PM | 15.05 | 2.48 | 82 | 23.35 | 8.30 | 155.20 | 1,288.19 |
| 6:00–7:00 PM | 15.05 | 3.00 | 99 | 17.35 | 2.30 | 145.57 | 334.82 |
| 7:00–8:00 PM | 15.05 | 2.83 | 85 | 15.05 | 0.00 | 139.48 | 0.00 |
| 8:00–9:00 PM | 15.05 | 2.00 | 70 | 15.75 | 0.70 | 125.93 | 88.15 |
| 9:00–10:00 PM | 15.05 | 2.00 | 39 | 22.92 | 7.87 | 133.07 | 1,046.85 |
As previously mentioned, the number of open primary Customs inspection booths was also recorded. Examining the previous tables shows the relationship between the volume of trucks moving across the border and the number of open inspection booths on the travel times, particularly in the inbound direction.
At the Blue Water Bridge, data collectors did not have to relocate due to an increasing queue length in the outbound direction, but did have to move in the inbound location. Several different locations along Highway 402 were chosen, depending on the current conditions. Of course, it was the easiest to record data at the initial location in the Canadian plaza as trucks approached the bridge. Here, they were moving slowly and were most often using only the rightmost lane. Two alternate locations were at or near the Indian Road interchange on Highway 402, approximately 1.4 and 1.8 miles from the initial location, respectively. Here, trucks would pass at highway speeds and would often use both lanes, reducing the number of vehicles that could be effectively recorded. Two additional locations were used when the trucks backed up beyond the Indian Road interchange. The first was at the Airport Road interchange, approximately 5.2 miles from the initial location. This area was in the construction zone and traffic was limited to a single lane. While vehicles still passed at full highway speeds, data collection was easier than at Indian Road due to the single lane of traffic. During the final days of data collection, the location was moved the next overpass closer to the bridge (0.55 miles closer than the Airport Road location) because of construction activity at the Airport Road interchange. On one occasion, the queue actually approached within a half mile of the adjusted Airport Road location. On another, the queue was approximately 4 miles long.
Specifically, the IB-1 collector had to move from the initial location around 2:25 pm on 6/12/01 upstream from the bridge. By approximately 2:40 pm, the queue had passed the Indian Road location and the collector had to move to Airport Road. This illustrates how quickly the queue can grow. That day, the collector remained at Airport Road until shortly after 4 pm. There was no queue the entire day on 6/13/01. On 6/14/01, the IB-1 collector moved to Indian Road at around 5:40 and then to Airport Road just before 6 pm. The queue had not yet dissipated by around 9:30 pm when data collection was stopped for the day.
The queue situation was different during the second week of collection. The IB-1 collector began collection at Indian Road at 6:30 am on 8/14/01. Approximately 12:45 pm, the collector moved to the alternate Airport Road location and remained there until the end of the day at 6:30 pm. Also, at around 8:30 am on 8/14/01, there was some construction activity on the roadway in one of the U.S. Customs primary inspection booths. This involved a significant amount of jackhammering and the adjacent booth was also closed because of the noise was too great for an inspector to function effectively. There were significant queues heading into the U.S. that day and the other three available booths were open for most of that time; however, it is unclear whether a fourth or fifth booth would have been opened if the construction were not taking place.
The queues continued on the second day of week two collection, 8/15/01, with the IB-1 collector again beginning at Indian Road (at 9:30 am). However, at 1 pm, the queue completely dissipated and the collector was able to return to the initial location on the bridge plaza. For the first time, however, the auto traffic began to interfere with the commercial vehicle traffic. As mentioned previously, trucks typically use the left two lanes when approaching the primary inspection booths and cars use the right lane. On this day, there was such an increase in auto traffic that impatient drivers were also occupying the center lane and once in a while a car would move into the far left lane. On three occasions between noon and 1:30 pm, the backup of cars extended from the auto inspection booths onto the bridge in all three lanes. This completely blocked truck traffic to the commercial lanes and would result in all the open truck inspection booths being empty for at least five to ten minutes until the next truck in line could pass by the cars in front of it. Also on 8/15/01, a truck became disabled in one of the open booths at 1:37 pm and was not towed away until 2:24 pm.
On 8/16/01, the IB-1 data collection began at Indian Road at 9:15 am and remained there until almost 10:30 am. However, the bridge remained fairly full of trucks and again there were a significant number of passenger cars. These cars temporarily blocked the trucks from approaching the inspection booths on three occasions, around 4:00, 3:45, and 4:40 pm.
For all days of data collection except the last (8/16/01), there were no weather conditions of note. However, there were alternating periods of light and heavy rain for most of the last day of collection until approximately 5 pm. Of particular issue, however, was the difficulty in reading license plates beginning at early dusk. While the locations near the bridge facility provided ample lighting, the illuminated headlights of approaching trucks effectively blinded the data collectors until the split second before the truck passed their location. This proved particularly difficult for the IB-1 collector who was recording trucks passing in excess of 60 miles per hour. The binoculars that all data collectors used to some degree made the glare even more pronounced.
The chosen locations for data collection proved to be well suited to the task. On several occasions, it would have been helpful to have specific written (rather than verbal) authorization from the local Canadian Immigration officials to facilitate processing at the primary auto Customs inspection as we entered Canada. On two occasions, the e-mail from the Vice Consul was insufficient for the Customs inspector and our staff were instructed to speak with the Immigration officials, "just to check". On both occasions, the Immigration staff were aware of our study and cleared us for entry, but we were nonetheless delayed. After the first occasion (our first pre-collection reconnaissance of the site), we requested some form of written documentation from Canadian Immigration and were told that we should not have any further problems, as they were aware of our study. On the second occasion, a Customs shift supervisor forgot to mention our presence to the morning shift of inspectors, which caused the delay.
Statistics
Table 20 shows the baseline or "no delay" travel time, the average travel time, and three other measures that indicate the reliability of the travel time estimates. The baseline time (in minutes) is the time needed to travel the study distance (between the starting point in the exporting country and the initial inspection point in the importing country) in free-flow traffic conditions. The average time is computed from all vehicles measured during the data collection period over the study distance. The 95th percentile time is the time (in minutes) within which 95 percent of all trucks can cross the border. The buffer time is the additional time above the average crossing time (in minutes) that it takes for 95 percent of all trucks to cross. The buffer index expresses the buffer time in terms of the average time and is the percentage of extra time that must be budgeted to cross the border within the 95th percentile time. For example, if the average time was 10 minutes and the buffer time was 5 minutes, the buffer index would be 50 percent.
 |
Baseline Time | Average Crossing Time | 95th Percentile Time | Buffer Time | Buffer Index |
|---|---|---|---|---|---|
| Outbound | 5.0 | 6.2 | 9.1 | 2.9 | 46.8 |
| Inbound | 11.1 | 34.2 | 80.3 | 46.1 | 134.8 |
From the table, it is apparent that both the average travel time and the reliability are significantly more favorable for outbound traffic than for inbound traffic.
Figure 10 illustrates the average travel time experienced for different truck volumes per lane per hour in each direction.
Figure 10. Average Travel Time for Different Hourly Volumes
Figures 11 and 12 show typical average hourly traffic volumes per booth for the study period as well as the measured average hourly travel times. In addition, the average number of open primary Customs booths in each direction is shown.
Figure 11. Typical Inbound Traffic
Figure 12. Typical Outbound Traffic
Conclusions
Lessons learned during data collection activities in this project at this site and at others along the Canadian and Mexican borders with the U.S. have identified several issues that should be taken into consideration to assist future data collection efforts. Some apply to advance planning and the initial site visit and others apply more specifically to the data collection activities themselves.
Planning and Site Visits
- Prior to conducting any data collection project, all jurisdictional and cooperating agencies should be made explicitly aware of the purpose and objectives of the study as well as all the details associated with the data collection project (e.g. dates, times, procedures to be followed during the data collection period, etc.). Failure to do so may result in confusion and possible delay of the study. This has been very time-consuming at some ports and should be adequately accounted for in the schedule. For some agencies, including U.S. Customs, it is important to contact both the federal and local levels. Some entities that should be contacted might not be readily apparent and can include construction companies working on public rights-of-way, state police, city officials, and Thruway Authorities. Some agencies provide verbal approval for the data collection and may even provide supporting documentation to their field staff, yet are reluctant to provide documentation for the data collectors to carry. Every effort should be made to obtain written authorization that can be carried by the data collectors, particularly from bridge authorities and immigration officials. Several times at some sites, the officer at the primary auto inspection booths asked data collectors to go to secondary inspection and speak with immigration officials. Although allowed to continue, this caused some unnecessary delay in the data collection.
- Prior to data collection activities, a general idea of traffic peak periods and conditions should be understood to optimize collection of appropriate traffic data and coverage of the appropriate times. This information should be obtained from discussions with knowledgeable officials and by examining historical traffic data.
- Any additional data needs should be discussed explicitly with the appropriate officials. At some crossings, for example, average hourly truck volumes are not normally recorded and maintained, but can be if special arrangements are made in advance. Alternatively, it may be appropriate to use other means to measure truck volumes, such as roadway counters or having the data collectors indicate the vehicles that pass without their license plates being recorded (assuming continuous data collection during each day). These additional traffic volumes could be used to corroborate data provided by the local authorities or used if their planned data collection did not occur or there was some other problem in providing the data.
- It is also important to be aware of special federal or local holidays on both sides of the border when scheduling data collections as these could affect traffic flows. Some minor holidays that occur on Mondays and Fridays, might not significantly affect traffic for a Tuesday through Thursday data collection period, but may increase the likelihood that key local officials will be on vacation and unavailable should any problems arise.
- When scheduling the data collection times, consider the availability of sunlight or high-powered lighting. It becomes increasingly difficult to read license plates at night as trucks approach with their headlights on (also a problem during rain) and entering the data into the PDAs also becomes more difficult when it is dark.
- Photographs of the border facilities and data collection locations should be taken during the site visits to assist in documenting the collection effort and to better inform the data collectors prior to their arrival on-site.
- Processing, data quality, and analysis of all traffic data require the largest portion of the study time.
Data Collection Activities
- Prior to data collection activities, an explanation and understanding of the procedures to be followed and logistics should be made clear to all members of the study team (e.g., number and location of license plate characters to be recorded, all commercial vehicles should be recorded, when and how to contact the on-site supervisor, etc.).
- Proper identification for all survey members and written documentation of authorization from all jurisdictional agencies should be carried at all times by all members of the study team, especially when conducting business in a foreign country.
- The supervisor should assess all conditions upon arrival for data collection to note any changes from the site visit or prior collection activities. Sometimes unplanned construction or other events may alter the preferred data collector locations or the truck flow patterns.
- While only one supervisor was originally planned for each data collection visit, it was determined that installing one supervisor on each side of the border was highly desired. One supervisor would be designated the overall site supervisor. This presented several benefits, the most important being added safety and security for the data collectors, particularly for a collector who needed to move to a remote location upstream from the border when the queue extended beyond their original location. Other benefits were increased awareness of current conditions and the origin of backups, the increased ability to relieve data collectors for breaks and lunch while maintaining continuous data collection, and assisting with data collection during exceptionally high-volume times or in difficult locations (such as remote spots along a highway when the vehicles were passing at free-flow speeds). Without the extra supervisor, a single supervisor would make repeated trips across the border to check on the collectors, relieve them, and provide them with food and drink if they were not conveniently located nearby. Border delays would often make this an extremely time-consuming process.
- For Mexican data collection, it is recommended that Mexican nationals be used, both as supervisors and as data collectors. This helps to enhance coordination with national, state, and local officials and to minimize the likelihood of immigration or other problems with federal, state, or local agencies.
- As mentioned above, the supervisors should be used to maintain nearly constant data collection during breaks. This improves data quality by ensuring the supervisors repeatedly observe each collector and can identify and correct any problems they might be having. Further, this improves the number of trucks matched at both the #1 and #2 locations, improving the sample size for analysis.
- Communication between the data collectors and their supervisors is crucial to an efficient and successful effort, particularly when one of the data collectors must move upstream past the end of a growing queue. Communication with the supervisor is also important when a data collector is having a problem with an official questioning their authority to do their work or when some other unexpected event occurs. For example, occasionally, there may be an anomaly with the data collection equipment and the collector can receive immediate instructions on how to proceed rather than having to wait until the supervisor next visits their location. Two-way radios (FRS-type with up to a two-mile range) and cell phones work adequately in most situations, but interference and range can limit their effectiveness. Cell phone service can be spotty near border areas. Additional longer-range communication options that do not require FCC approval should be considered for future collections. Obviously, when using cell phones, ensure that long-distance charges and roaming fees will not be significant costs.
- It is important to ensure that the data collectors are safe and comfortable during their long periods of collection. If their data collection locations cannot provide adequate cover from severe rains or heat, additional vehicles should be considered. Comfortable sport chairs with attachable beach umbrellas served to protect the collectors well during light rain and moderate sun. Ensure that the collectors have an adequate supply of water and that facilities are conveniently accessible. This becomes more difficult for the remote locations upstream from the border crossing.
References
Turner, S. M., W. L. Eisele, R. J. Benz, and D. J. Holdener. Travel Time Data Collection Handbook. Report No. FHWA-PL-98-035. Federal Highway Administration, Texas Transportation Institute, March 1998
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