Interior design. The design of the proposed development shall ensure safe interior circulation within its site with adequate ingress and egress as well as separation of pedestrian, bike ways, and vehicular traffic. The principal roadways serving the site shall be designed to conform to standards of the Town, as established by the Town's Subdivision Rules and Regulations, subject to waiver by the Planning Board, after review and guidance by emergency services and the Department of Public Works, upon a showing of good cause by the applicant.