15 Identify two aspects of road design that might be affecte

15. Identify two aspects of road design that might be affected by the characteristics of a design vehicle.

Solution

There are various characteristics of a design vehicle that may affect road design, for example,

1. vehicle dimension: for example vehicle length may affect safety through interactions with other vehicles, such as passing maneuvers and in clearing intersections, in addition to its influence on vehicle handling and stability. Also it can change the various design parameters such as space headway, overtaking sight distance. The width of vehicle affects the width of lanes, shoulders and parking facility. The capacity of the road will also decrease if the width exceeds the design values. The height of the vehicleaffects the clearance height of structures like over-bridges, under-bridges and electric and other service lines and also placing of signs and signals.

2. weight and axle configuration: The weight of the vehicle is transferred to the pavement through the axles and so the design parameters are fixed on the basis of the number of axles. The power to weight ratio is a measure of the ease with which a vehicle can move. It determines the operating efficiency of vehicles on the road.

3. turning radius: This is also important at an intersection, round about, terminals, and parking areas. The minimum turning radius is dependent on the design and class of the vehicle. The effective width of the vehicle is increased on a turning.

4. Visibility: dimension of the vehicle and the slope and curvature of wind screens, windscreen wipers, door pillars, etc