Section 1221(a) in Police Regulations, Bengal , 1943
(a)Police officers of all grades below the rank of Inspector on escort duty are entitled to their actual expenses as laid down in clause (b) (except for journeys by railway or steamer) within the limit of the travelling allowance admissible under the Fundamental and Subsidiary Rules. When the journey beyond jurisdiction exceeds 20 miles by road they may exchange their daily allowance plus actual baggage expenses for mileage allowance but in that case actual baggage expenses cannot be charged in addition - see S. R.s 66, 63, 69, 81 and 83.