Since about one-third of the day’s traffic is known to pass over the streets during the two peak periods, totaling about 4 hours a day, the average speed of the all-day movement can be readily computed as 21.7 miles per hour, a speed at which it takes 2.77 minutes for a vehicle to travel a mile.
Time savings through improvement
The annual travel on sections of the system in cities of 5,000 population or more is 17,180 million vehicle-miles. The aggregate travel time for this movement at the prevailing speeds is 47,589 million vehicle-minutes. If the average speed of the movement were increased to 35 miles an hour, the minimum that would be required if the streets were adequately improved, this time would be reduced by 20,919 million vehicle-minutes annually, taking into account the increased traffic that would have used these streets had they been so improved, and the shortened mileage resulting from the improvements At a cent a minute, this time saving would be worth more than $209 million annually, a sum about four-fifths as great as the annual cost of urban improvements hereafter proposed, spread over 20 years. In addition, the elimination of much stopping and starting would effect tangible and material savings of a larger order in reduced gasoline consumption and vehicle maintenance costs.
