Political voices on both sides of the Columbia River are striking a positive tone and avoiding past battles as they launch a second effort to replace the Interstate 5 Bridge.

Lurking beneath the veneer of tranquility are the same issues that polarized the region a decade ago: opposition to tolling, hostility toward light rail, support for a third Columbia River bridge, concerns about climate change, and a sneaking suspicion this $3 billion-plus megaproject will cost too much and deliver too little.

Nearly $200 million was spent on the Columbia River Crossing. The project achieved important milestones, including the federal government’s December 2011 decision that it had met the National Environmental Policy Act’s stringent provisions. Eighteen months later, the project fell apart when the Washington Senate failed to match Oregon’s $450 million contribution to launch construction.

The size and complexity of such a massive project can lead to its downfall.

“Most megaprojects don’t succeed,” said Aaron Shenhar, an international expert on project management and CEO of The SPLWIN Group in Verona, N.J. “If anybody starts a megaproject today, they must realize that their chances for success are as good as the statistics.”

Officials are optimistic a new set of local and state political leaders, coupled with mounting frustration over daily traffic jams and the potential to substitute bus rapid transit for light rail, will make the project’s reboot successful.