Citation

Conner MA, Hiller SH. Highw. Res. Board bull. 1956; 130: 69-75.

Copyright

(Copyright © 1956, National Research Council (U.S.A.), Highway Research Board)

DOI

unavailable

PMID

unavailable

Abstract

Two general kinds of digital computation problems are very amenable to machine computations. The first kind is the performing of highly repetitive calculations for a mass of data. An example of this is the application of the traffic diversion curves to the assignment of traffic using o & d trip information. The second kind of computation is the performance of a great number of sequential calculations starting from a single set of data. An example of this is the distribution of individually forecasted zone trip frequencies by successive approximation. Some of the advantages of punched card machine computations are greater speed, greater accuracy, freeing of technical personnel from routine calculations and the solution of problems that would otherwise be impossible or so time consuming as to never be attempted. The amount of computation involved in the assignment of traffic to a selected line can be very great. The number of theoretically possible movements is the combination of zones and stations taken two at a time or by a formula in which 'n' is the number of zones or stations. Machine computations on an ibm-602a enable the work to be do done in 1/2 to 1/3 the time required using desk calculators. More advanced type calculators such as the remington rand 'f 'file computor' or an 'ibm-650' would permit a much greater time saving. The advanced computer have an added feature of internal automatic checking. Alternate route possibilities are measured using map meters. This information for each zone-to-zone movement is key punched and verified. The time ratios are than computered by machine using assumed arterial street speeds and assumed expressway speeds. The cards are then collated with a rate deck and diversion percentages reproduced. The cards are then run through the calculator again to find the estimated expressway usage. The final step is to make an 'on-off' tabulation from which the assigned traffic is entered on the expressway line. A specific application is cited and a number of additional machine applications are mentioned.