60
INTERREGIONAL HIGHWAYS
1,000,000 persons. As will be observed, the studies made at 3 cities of 300,000 or more population show that upward of 90 percent of the traffic moving toward these cities on main approach highways consisted of vehicles bound to ultimate or intermediate destinations within the cities themselves. For the 4 cities of 50,000 to 300,000 population, the similar proportion of city-bound traffic was found to be above 80 percent. For the smaller cities, the corresponding proportion tends to decline, reaching 50 percent for the cities of less than 2,500 population that were studied.
Figure 29.—Graph showing two divisions of the total traffic on roads approaching representative cities of various population groups: (1) The average percentage city bound, and (2) the average percentage which could have bypassed the cities.
Table 14.—Proportions of traffic bound to and beyond cities of various populations, as shown by origin-and-destination surveys on highways approaching 27 cities
| Population group | Number of cities |
Traffic bound to the city |
Traffic bound beyond the city |
| Percent | Percent | ||
| Less than 2,500 | 6 | 49.3 | 50.7 |
| 2,500 to 10,000 | 6 | 56.7 | 43.3 |
| 10,000 to 25,000 | 3 | 78.1 | 21.9 |
| 25,000 to 50,000 | 5 | 79.0 | 21.0 |
| 50,000 to 100,000 | 2 | 83.8 | 16.2 |
| 100,000 to 300,000 | 2 | 81.6 | 18.4 |
| 300,000 to 500,000 | 2 | 92.8 | 7.2 |
| 500,000 to 1,000,000 | 1 | 95.8 | 4.2 |
