However you can restrict what local government gets to pick from so that there's less arbitrary variation.

For example we don't need a code in one town that requires ramps with inclines no more than 15% and maximum distance between flat stages of 10 metres, then the next town has 2 in 11 inclines and vertical climb between stages maximum two and a half feet. They both actually want "You know, a ramp, for like wheelchairs and prams and stuff" and they shouldn't be left to make up the specifics.