Question

1. describe how the driver and vehicle characteristics influence the geometric design of the highway

2. describe design standards for major parts of highway

Answer 1

Ans(01) : The characteristics of driver as well as vehicles have major role in deciding the geometric design of the highway. Drivers intend to operate vehicles at safe speed based on the roadway geometric features. These features would be differentiated and characterized by gradient, horizontal and vertical curvature, superelevation or the length of the curve. The driver eye level is being used for estimating the various sight distances and the quality of vehicles are also important for obtaining the design speed of the vehicle. Various types of vehicle have different limits to the operating speed on the highways as luxury cars would have greater permissible speed as compared to the trucks of heavy weights. Vehicle drivers would continuously make decisions and would execute them at the time of driving on the roadways. It is also being observed that the average operating speed of the vehicle is usually greater than the design speed of the highway.

Ans(02) : There are different design standards that are being used at the time of designing parts of highways. These standards would help in safety and maintenance of the road. There are various standards that are being used at the time of designing of any highway and are listed below :

1. Design speed and traffic volume of the highway.
2. No of lanes. More the traffic, more will will be the lanes provided and average speed would be increased.
3. Lane width along with the number of lanes.
4. Various sight distances.
5. Alignment and grades.

All the above standards should meet the expectations and there are some others also as these standards would help in providing quality highway and die to that it is being used in major parts of the highways.