Correct Answer - Option 4 : both (volume of traffic) and (speed of train)
Explanation:
Gauge of Railway track:
(i) The gauge of a railway track is the clear distance between the running faces or gauge faces of the two rails. Running faces are the inner faces of the rails in india, we have three types of gauges
- Borad gauge (BG) = 1.676 m
- Meter gauge (MG) = 1.0 m
- Narrow gauge (NG) = 0.762 m
(ii) A larger gauge has the advantages of greater traffic capacity, speed and safety. However, it requires flatter gradients and curves.
(iv) Factor responsible for selection of gauge:
- Cost of construction
- Volume and nature of traffic
- Development of under developed area
- Physical features of the country
- Speed of vehicle movement