Commuters, downtown residents, and bus riders have been seeing more of downtown since August, when construction of the library lot parking structure shut down Fifth Avenue, the city’s main southbound artery. Drivers accustomed to breezing through the one-way street’s well-timed lights now must either detour four blocks west to First Street or crawl through rush-hour gridlock on Main St. or Fourth Ave. So why did the city decide to tear up such an important street for so long?

“Going under Fifth allows us the possibility of entry and exit on the ramp on South Fifth,” explains Adrian Iraola, the DDA’s project manager. Going under the street will allow cars to enter from the west side of Fifth, by the post office, rather than the east, by the library. “There may be a time when that [east side] would be blocked by construction activities, and this will allow us to have construction above the parking structure without impeding the exits,” Iraola explains.

A DDA-funded study just came out in support of a conference center on top of the structure–though it didn’t address the crucial question of who would subsidize its operating losses. Whatever happens atop the structure, the detours will continue for most of the new year. “It is scheduled that this block will reopen December 2011,” says DDA executive director Susan Pollay, “if not before.