Section 6(a) in Gauhati University Travelling Allowance Rules, 1966
(a)For the purpose of calculating mileage allowance, a journey between two places is held to have been performed by the shortest of two or more practicable routes, or by the cheapest of such routes as may be equally short ; provided that when there are alternative railway routes and the difference between them in point of time and cost is not great, mileage allowance should be calculated on the route actually used.
