Soon, for a time at least, the circle will be unbroken.

The eternally clogged intersection at Columbus Circle seems to have been under construction forever. After two years and $20 million, however, the latest of its construction projects is essentially complete, slightly late but slightly under budget. A ribbon-cutting ceremony with Mayor Bloomberg is being planned for later this summer.

The circle, at the southwestern corner of Central Park, was enlarged, landscaped, and outfitted with a high-tech fountain that encircles the monument. The surrounding streets were rebuilt with new sidewalks, curbs, lights, water mains, and sewers.

“This was not our everyday project,” the assistant commissioner of the city’s Department of Design and Construction, Evans Doleyres, said. “Our normal problems were magnified tenfold.” The agency oversees and executes city construction projects.

The project was scheduled for completion in late 2004, but builders had to reroute traffic from six major thoroughfares, carve an underground control room the size of an apartment into a bed of solid underground rock, and juggle jurisdictions with an alphabet soup of city agencies.

Stakeholders included the departments of transportation and environmental protection, Con Edison, New York City Transit, Parks and Recreation, the Central Park Conservancy, the Landmarks Preservation Commission, the Art Commission, the Municipal Art Society, local community boards, and the big construction project next door: the $1.7 billion Time Warner Center.

Last to be completed is a fountain with two concentric rings of arching water, which was developed by WET Design, the team that built the fountains at Las Vegas’s Bellagio Hotel and Casino and the Brooklyn Museum. An underground computer coordinates the sequencing of water spurts, adjusting for wind changes, and is connected by modem to the designer’s office in Los Angeles.

Long, curved benches made from ipe, a tropical hardwood, surround the basin.

“When you go in there, hopefully the noise of the city will be drowned out. The water is a clue that you are in a special place,” a representative of the landscape architecture firm Olin Partnership, Allan Spulecki, said. “The center emanates out, becoming a bull’s-eye in an urban center. Columbus Circle is in a very special spot in New York.”

The monument is the point where distances to and from the city are officially measured.

The 40-foot marble monument of Columbus, by the Sicilian sculptor Gaetano Russo, was erected in 1892, the 400th anniversary of the explorer’s journey to what became America.

In 1991, the statue was restored in preparation for its centennial, and seven years later, the city turned Columbus Circle into a real circle, changing traffic configuration, improving pedestrian access, replanting, and installing benches. The current project began in 2003.

Its completion, however, will not forever banish the orange cones. The statue is to undergo another restoration before Columbus Day this October, and the Museum of Art and Design hopes to proceed this fall with its controversial plan to renovate and move into the “lollipop motif” building, designed by Edward Durell Stone, at 2 Columbus Circle.