The tremendous growth of motor transport in the United States has impelled the States and municipalities to lay down numerous rules specifically setting forth the application of the basic right hand rule in various situations. For example, a vehicle meeting another must give the other vehicle half the road. A vehi cle may not overtake and pass another on sharp curves or hill crests and not unless there is space ahead of the overtaken vehicle to permit the overtaker to regain safely his own side of the road. The operator of the overtaken vehicle must on signal give the overtaker ample opportunity and must not increase his speed until the other vehicle has passed him completely. It has been assumed that the overtaken vehicle will normally be near the right hand edge of the roadway, but with the development of wide streets with several definite lanes of traffic in each direc tion, there has been a growing tendency of operators to keep toward the centre. A rule has therefore been developed requir ing slow moving vehicles to keep as far to the right as possible.
One of the most essential and also most difficult rules of the road to define and enforce equitably is the right of way rule at intersections. The fundamental rule is that the vehicle which would first reach the common point has the right of way. Sup plementary to this rule is a provision of wide prevalence requir ing the vehicle on the left to yield to one on the right approach ing the common point at approximately the same time. A further qualifying provision in some jurisdictions is that giving right of way to the vehicle which first entered the intersection. Other
widely accepted provisions are those giving emergency vehicles the right of way over other vehicles regardless of relative posi tion at an intersection; and the through street stop rule, which requires all vehicles to come to a full stop before entering cer tain thoroughfares designated for high-speed through traffic, and placing upon the cross traffic the same added burden of responsi bility that is upon any vehicle starting from a position of rest.
Recognizing the danger, particularly at night, of pedestrians on highways without separate footpaths being run down by motor vehicles coming from the rear, it is regarded as generally safer for them to walk on the left side. A few States have passed laws requiring this. Such laws, however, would compel the pedes trian to walk where it is at times manifestly unsafe, as on the inside of a sharp curve, and virtually deny him right of way on any other part of the roadway. A vehicle turning to the right is generally required to keep close to the right curb or edge of the roadway, while, according to the prevailing rule, a vehicle turning to the left must do so from the traffic lane next to the centre line of the roadway. The most modern and approved speed restrictions embody a general prohibition against driving too fast for the conditions, together with prima facie limits, for the guidance of operators and enforcement officers, beyond which the apprehended operator must prove that he was driving safely. The prima facie limits are ordinarily graded from business dis tricts to rural areas. (A. B. B.)