Sound Transit and Seattle Department of Transportation officials outlined eight potential options to connect Ballard to downtown Seattle via light rail or at-grade streetcar at a briefing yesterday, with potential price tags ranging from $500 million or less to as much as $3 billion. Sound Transit staffers emphasized that the prices attached to the different options were for comparative purposes only—the agency hasn't done formal cost estimates yet.

The main differences between the options involve technology (the most expensive alternative is a long tunnel that would go under the Ship Canal); route (some routes roughly parallel the existing RapidRide bus route through the west side of Queen Anne and up 15th Ave., while others veer west, either crossing the top of Queen Anne or running along Westlake or Dexter near South Lake Union before heading to Ballard through Fremont) and, for the six options that don't involve a Ship Canal tunnel, bridge design (more expensive options feature a 140-foot-high fixed bridge much like the Aurora Bridge, while others include a 70-foot movable bridge that would open for tall boats; one option would use the existing Fremont Bridge). The existing 44-foot-high Ballard Bridge is not considered as a crossing in any of the options. 

The most expensive options Sound Transit is considering include tunnels of varying lengths; the $3 billion option would involve a new downtown tunnel under Second Ave. (a block away from the existing downtown tunnel, which will be at capacity by the time the new route to Ballard might open in the 2020s, and, incidentally, along the same path as the the moribund proposed monorail),. From there, the tunnel would pass through Queen Anne, surface and run on elevated tracks through Interbay, and go back into a tunnel across the Ship Canal into Ballard, stopping at Market Street. 

A cheaper option, in contrast, features exclusive lanes for rail (similar to the existing rail lanes on MLK Jr. Way SE), with a two-way couplet on Second and Fourth Aves. downtown. Sound Transit included a two-block gap between the north- and southbound trains, agency project manager Karen Waterman said, so that buses can continue to use Third Ave. without interference from trains.

Cheaper still are options that do away with exclusive right-of-way altogether. In those options, both priced at $500 million or less, streetcars would share lanes for all or part of the route (along the east side of Queen Anne, on Dexter or Westlake) with cars, much like the South Lake Union trolley does today. This dramatically reduces costs (both options featuring shared lanes are priced at $500 million or less), but it also increases travel times, as streetcars have to compete with general traffic for space.

Sound Transit planning director Ric Ilgenfritz said a Ballard-to-downtown rail proposal, the first new rail corridor for the agency since Sound Transit 2, in 2008, could be "incorporated into a new ballot measure two or three years down the road."

Ilgenfritz said that in the options that show light rail paralleling RapidRide, it's possible that RapidRide service could be reduced or eliminated. Metro, he said, is "engaged in this process, and obviously, half their board sits on our board. Ultimately, there’s a decision to be made about how much service you need in the corridor to serve the demand that's there." 

Running trains on Second and Fourth Aves. would require lane reductions, on two downtown streets that are currently used by Sound Transit routes serving North End suburban commuters. Ilgenfritz said that once light rail reaches Northgate (in 2021) and Lynnwood (in 2023), most of those route (including the 510, the 522, and the 550) will be "intercepted" by rail and won't continue downtown. 

Check out all the alternatives here; and weigh in tonight at Sound Transit's open house in Ballard, from 5–7pm at the Ballard High School Commons, 1418 NW 65th St.