As one of the first cities in the U.S. to lid a freeway when Freeway Park covered Interstate 5 in Seattle in 1976, the attraction of freeway lids has never fully dissipated from the minds of those in Seattle. And now a new volunteer group, dubbed LID I-5, has restarted a push to create more freeway lids through downtown.

While the history of freeway lids in Seattle—from Freeway Park to more recent additions on State Route 520 heading east from downtown—offer lids as a park solution, this group, with backing from both park and affordable housing associations, says the city should study the viability of adding lids throughout downtown for a variety of uses, including parks and affordable housing, but also retail and a list of other ideas.

As Seattle’s neighborhoods of Downtown, Capitol Hill, South Lake Union and Uptown continue to grow in both residential figures and jobs, LID I-5 says open space, affordable housing and even space for schools continues to dwindle. Without official government standing, the prime push of the group right now includes generating enough momentum so that the city takes up an official study of lids on the freeway.

Leaders of the group say that in dense cities space remains a premium and lids can create new land for varied public and private use while helping resolve social and environmental issues created by a freeway that cuts off neighborhoods. While acknowledging that parks remain the leading use of lids across the country, the group says “lids also cut off the noise and sights of sunken freeways, transforming one of the least desirable places in the city to one of the most attractive.”

With the purchase price of buying new land in Seattle hovering around $1,000 per square foot, the group says the average cost for constructing a lid comes much less expensive at $500 per square foot, adding value both publicly and privately in Seattle.

Through much of downtown Seattle, I-5 cuts a groove-like wedge into the city below the street level grade. LID I-5 wants the city to focus its effort on studying that area, but then expand its study beyond the main downtown core.

Seattle has led the way in adding lids to freeways in the past and has never fully abandoned the idea, as seen with the recent State Route 520 project. We’ll see if a renewed public push can reignite the idea of adding lids on I-5.

Follow Tim Newcomb on Twitter at @tdnewcomb.