Seven new Metrobus routes have been proposed in a bid to cut congestion and get more people using public transport.
It is part of an 18-year transport strategy run by councils across the greater Bristol area.
A council report says the routes have been chosen to enable sustainable economic growth, accessibility, and accommodate new housing and employment growth.
If all schemes are approved the total bill could top £700m.
The routes being considered include:
- Bristol city centre to Avonmouth and Severnside
- Bromley Heath to Yate
- Bower Ashton to Nailsea and Clevedon
- Bristol to Bath along the A4
- Bristol Parkway to The Mall at Cribbs Causeway via Patchway
- An orbital route connecting south Bristol to Emerson's Green
- Weston-super-Mare town centre to the M5 junction 21 developments
The plans, if approved, will go out for public consultation in January.
Two out of three of Bristol's Metrobus routes are in service now at a cost of about £230m - the m2 service connecting Long Ashton park-and-ride and Temple Meads railway station, and the m3 between Emerson's Green and the city centre.
The controversial transport scheme has been dogged by delays on ticketing systems and buses which did not fit properly in guided rail sections.
It has also been beset by spiralling costs and has caused delays due to lengthy roadworks, which have caused disruption on roads in the Bristol area.