Eight years from now, Wellingtonians could be jumping on sleek electric buses, twice the size of the current ones, and cruising up the middle of Kent and Cambridge terraces while cars on either side slam on their brakes at traffic lights.

That scenario was made possible yesterday when the region's leaders voted to advance plans for a $268 million bus rapid transit network between Wellington's CBD and the suburbs of Newtown and Kilbirnie.

Many of the finer details are yet to be worked through, but at this stage it is thought taxpayers will foot half the bill while Wellington City and regional ratepayers divvy up the remainder.

The decision is the final nail in the coffin for light rail - a project that Wellington Mayor Celia Wade-Brown promised to push for when she was first elected to the top job in 2010.

"From what I've seen of the studies that compare them, light rail is much more attractive for getting people to choose to use public transport than a bus system, which is beginning to suffer from congestion in its own right," she told The Dominion Post shortly after that election victory.

But she was firmly on board with the new bus project yesterday, saying their ability to go further than light rail, to outlying suburbs such as Karori, Miramar and Island Bay, made them a winner.

Her council has left the door slightly ajar for light rail, however, by moving to protect Constable St, between Newtown and Kilbirnie, as a public transport route.

If space can one day be found to run electric trams along Constable St, it will eliminate the need for a $380m rail tunnel through Mt Victoria, which was a big reason why light rail blew out to an unpalatable $1.2 billion.

Detailed plans for bus rapid transit will be drawn up over the next 12 to 24 months.

They will involve articulated or double-decker buses running along a dedicated busway, where possible, and getting preference at traffic lights.

Ms Wade-Brown said Wellington's topography would make it difficult to build the type of busway seen oversees, which was separated from traffic by barriers for its entire length.

"This is not going to be the highest quality bus rapid transit network in the known universe, because that just wouldn't work [in Wellington]."

Regional council chairwoman Fran Wilde said the gap between electric trams and buses in terms of technology and attractiveness was getting smaller and smaller.

A lot of cash had been spent on improving the region's commuter rail network in recent years and it was time bus users saw some hefty investment, she said.

The decision to shelve light rail did not go down well with regional councillors Sue Kedgley and Paul Bruce, who were not convinced the new buses would fit in places like Manners St.

"Longer, bendy buses pose a risk to pedestrians and cyclists, as they are difficult for drivers to manoeuvre on our narrow streets," Ms Kedgley said.