Downtown Areas

The following excerpt was taken from the1992 edition of the Transportation Planning Handbook, published by the Institute of Transportation Engineers (p. 177).

Looking at CBDs in general, the following relationships are typical:

1. On-street (curb) parking is related to city population, typically decreasing to about 10 percent of total supply in cities over 250,000 population.
2. The demand for long-term, work purpose parking increases with population size, ranging from 20 percent of total parkers for cities under 100,000 to over 30 percent for cities approaching 1 million or more population.
3. The average walking distance increases with city size.
4. The parking duration varies by trip purpose and population size. Work trip and residential parking exhibit the longest durations, while durations for all trip purposes increase with city size.
5. The parking turnover at the curb is usually three to four times greater than for off-street spaces. At all facilities, turnover is influenced by the type of parker, the rate structure, local regulations, and enforcement levels. Furthermore, larger cities generally experience lower parking turnover than smaller cities.
6. Parking accumulation peaks between 11:00 A.M. and 2:00 P.M. in the average CBD; however, different trip purposes exhibit unique accumulation patterns. The peak accumulation seldom exceeds 85 percent of the total parking supply, even though parts of the area are severely deficient in parking supply (location is the key factor). Peak accumulation tends to increase with population size, but at a diminishing rate.