Figure 1. As average vehicle speed increases, the time required to evacuate moves asymptotically toward 25 hours.
| Input Parameters / Assumptions | |
|---|---|
| Number of People (millions): | 3 |
| Average Number of People per Car: | 4 |
| Number of Lanes (Est. 3 freeways with 4 lanes each): | 12 |
| Average length of 1 car (feet): | 20 |
| Number of car lengths per 10 mph of speed (recommended safe distance is 1 car length per 10 mph): | 1 |
| Average Vehicle Speed (mph) | Length of 1 Car plus Number of car lengths per car | Feet traveled per minute per car | Number of cars per minute each lane | Number of cars per hour each lane | Total number of cars per hour | Time Required To Evacuate People (Hours) |
|---|---|---|---|---|---|---|
| = 1 + (mph) / (0.1 * (num car lengths per 10 mph of speed)) | = (mph) * (5280 ft/mile) / (60 minutes per hour) | = (feet travelled per minute per car) / ((avg length of car) * (number of car lengths per car)) | = (number of cars per minute) * 60 | = (number of cars per hour) * (number of traffic lanes) | = (number of people) / ((avg number of people per car) * (number of cars)) | |
| 10 | 2 | 880 | 22 | 1320 | 15,840 | 47.4 |
| 15 | 2.5 | 1320 | 26.4 | 1584 | 19,008 | 39.5 |
| 20 | 3 | 1760 | 29.3 | 1760 | 21,120 | 35.5 |
| 25 | 3.5 | 2200 | 31.4 | 1886 | 22,629 | 33.1 |
| 30 | 4 | 2640 | 33 | 1980 | 23,760 | 31.6 |
| 35 | 4.5 | 3080 | 34.2 | 2053 | 24,640 | 30.4 |
| 40 | 5 | 3520 | 35.2 | 2112 | 25,344 | 29.6 |
| 45 | 5.5 | 3960 | 36 | 2160 | 25,920 | 28.9 |
| 50 | 6 | 4400 | 36.7 | 2200 | 26,400 | 28.4 |
| 55 | 6.5 | 4840 | 37.2 | 2234 | 26,806 | 28.0 |
| 60 | 7 | 5280 | 37.7 | 2263 | 27,154 | 27.6 |
| 65 | 7.5 | 5720 | 38.1 | 2288 | 27,456 | 27.3 |
| 70 | 8 | 6160 | 38.5 | 2310 | 27,720 | 27.06 |