The two candidates who support the city’s planned rail system saved most of their barbs for each other as the three hopefuls vying for Honolulu mayor faced off tonight in the first live televised debate of the campaign.

Mayor Peter Carlisle and former city Managing Director Kirk Caldwell had several pointed exchanges, notably over the other’s job performance and who deserved credit for certain successes, while former Gov. Ben Cayetano picked his spots to try and score points.

The debate, co-sponsored by the Star-Advertiser and Hawaii News Now, touched on various topics but, as in their debate three weeks ago, much of the discussion continually circled back to the issue of rail.

Cayetano, the perceived frontrunner and the only one opposed to the city’s planned $5.27 billion rail project, was pressed for details on his transit alternative and was criticized for failing to deliver specifics.

Cayetano has vowed to kill the project and instead seek to use the money for improvements to roads, sewers and the bus system.

When asked for details of his bus plan, Cayetano referenced a 2003 study that indicated a bus rapid transit system would cost about $1 billion, but he envisioned it costing less.