Section 4(3)(a) in U.P. Housing and Development Board Regulations, 1982
(a)The minimum width of a service road shall be 9m. But a road adjoining a park or any open public space with building only on one side may however have a minimum width of 7.5m. The 9m. service road can serve up to a length of 300m. This will be measured from one wider street to another wider street. In case of 7.5m. wide road it can serve upto 400m.