3 Suggest a desirable road classification for the following

3. Suggest a desirable road classification for the following design scenarios: a) A road that links an arterial to a freeway, with AADT of 8,000 with 15% trucks, expected running speeds of 80 km/h with traffic movement a preferred consideration over land access. b) A road that connects to two arterials, with AADT of 9,000, intersection spacing of 200 m, 24 m right of way, occasional sidewalks, special facilities for cyclists, potential for transit service, with an expected running speed of 50 km/h.

Solution

1. for the given freeway the AADT is 8000 and the % of trucks is high which indicates the need of an expressway.

The avg speed rounds upto 80kmph which indicates an Highway requirment.

According to Indian Road Congress the road can be classified as a ClassAA road of 20 m width ( includes divider, side lanes) which can carry an avg load of 70 tonnes for a interval of 30m which is for more safer than the given interval and load .

2.

the given value of AADT is 9000 but here it is given that the road is connecting two arterials so the value of AADT can be doubled and in addition to that sidewalks, potentila for transit service and cycleways are included which may rounds upto 10% of AADT i.e.20000 AADT.

So according to IRC the class70R clasified road with an expressway of four lane traffic with a cummulative width of 30 m ( which includes sidepaths, transit way, walkways on either sides, dividers)