I share my office with a noise consultant. Recently I worked with him on a project to investigate "Effects of Road Texture on Traffic Noise and Annoyance at Urban Driving Speeds". The project was formulated as a consequence of public complaints occurring after road surfaces were changed as part of regular street maintenance. We investigated road noise associated with different types of surface, by taking noise measurements of general traffic and control vehicles, and also by surveying residents about their annoyance with road noise. We picked roads that were about to be resealed, and surveyed before and after they were resealed, to pick up on any changes in annoyance. It was found that surface type was significant in influencing traffic noise annoyance of people living next to the roads, and that changes in behaviour could be detected for very small changes in noise, i.e. less than 2dBA. This is significant because current noise models predict only minimal effects of road surface type at urban driving speeds. My colleague has just presented a paper on this research at the Internoise conference in Chicago.
Anyway! getting back on track, I know that one of the major international models for calculating road traffic noise is the CRTN:
Department of Transport (DOT) (Welsh Office) 1988 Calculation Of Road Traffic Noise. Her Majesty’s Stationery Office, London
My colleague is still away at the moment, but if you require any further help, he has lots of information about standards for traffic noise in residential areas.