Seventeen months before the big vote, former Gov. Gary Locke is recruiting a high-powered committee to promote a ballot measure for more highways and transit lines in urban King, Snohomish and Pierce counties.

Locke is serving with two co-chairmen on opposite ends of the political spectrum: John Carlson is a conservative radio talk-show host who lost the governor's race to Locke in 2000 and last year backed a losing initiative to cancel a gas-tax increase. Jessyn Schor is executive director of the pro-transit Transportation Choices Coalition.

Their Puget Sound Transportation Roundtable is only an advisory board, but it is expected to include labor, environmental and business leaders whose clout and money might influence what local politicians send to the November 2007 ballot.

The Regional Transportation Investment District, led by members of the county councils, will choose which highway projects will be voted on. Meanwhile, Sound Transit is discussing its "ST2" package that likely will feature light-rail extensions and park-and-ride garages.

If voters reject either of the 2007 ballot measures, both fail.

The highway package totaled $7 billion as of January, while Sound Transit may seek a comparable amount. That's in addition to a Seattle streets measure and a King County bus measure this year.

In an e-mail to recruit committee members, Locke said that early next year the group "will mount an aggressive public-education effort in support of the proposed investments, before handing matters off to the actual ballot campaign."

The idea of bringing together such differing political views came from the Discovery Institute's Cascadia Center, which has pledged $30,000, and the Gallatin Group, a consulting firm.

Staff reporter David Postman contributed to this report. Mike Lindblom: 206-515-5631 or mlindblom@seattletimes.com