§ Mr. Marples
Justification for a pedestrian crossing depends on a number of factors. The most important are the numbers of pedestrians and vehicles at the site, but these numbers would in differing circumstances be given different weight, which precludes a decision on the basis of traffic flows only. Also relevant are the conditions at the site, including width of road, existence of central refuges, the proximity of other facilities, and the attraction of the site as a natural crossing point.
These factors apply also to pedestrian subways which are particularly required where the traffic is so heavy that pedestrians would have considerable difficulty in crossing on the surface, and where it would be undesirable to impede the traffic flow. The high cost of providing subways has also to be taken into account.