New bridges for vehicles to cross the Brisbane River are unlikely to be built, with Lord Mayor Graham Quirk saying pedestrian and public transport projects were the focus of the future.

The Lord mayor revealed that building river crossings was becoming more difficult at his State of the City address on Tuesday evening.

RACQ head of public policy, Rebecca Michael, said traffic into the CBD would become more congested and the capacity of how many vehicles that could be brought into the city was being reached.