Are you thinking of moving or widening your driveway over a few feet and you have no money to hire an architect or engineer? Check out this site. There are tons of details that you can use as a guide for your project. Page R-30 show you some basic requirements for driveway design in the City & County of Honolulu. For residential districts, driveway must be between 12 to 25 feet in width. Two driveway is allowed if added up to 25 feet in total width. For business district, driveway must have minimum width of 12 feet and 20 feet for two way traffic. Maximum driveway width is 30 feet or 45% of property frontage but less than 50 feet. I hope this help. If your project is more complicated than just moving the driveway, it is wise to consult an engineer or architect.
http://www.usspecbook.com/files/specs/standard-details-public-works-construction.pdf
