A new flyover ramp at Interstate 5 and State Route 18 officially opened Monday in Federal Way, six months ahead of schedule.

The ramp takes drivers from westbound SR 18 to southbound I-5. More than 20,000 vehicles are expected to use the ramp daily.

A second ramp, which opens July 23, will take drivers from eastbound SR 18 to northbound I-5. A ramp from SR 18 to SR 161 is still under construction and will open in September, according to the Washington State Department of Transportation.

The entire interchange is known as the Triangle Project, where I-5, SR 18 and SR 161 converge. The project will reduce congestion and collisions at the heavily traveled exchange.

With a price tag of $112 million, the project’s original completion date was April 2013. Mowat Construction broke ground on the project in August 2010.

Economic impact

A collaboration among federal, state and local leadership made the project possible. Congressman Adam Smith (D-District 9) secured funding at the federal level, while State Sen. Tracey Eide (D-District 30) got the effort rolling in the Legislature in 1993.

“It’s been an idea that was generated from the city level up,” Smith said at Monday’s ribbon cutting. “This is a key point for our economy in the South Sound region.”

The primary funding for the project stemmed from a gas tax increase in 2003 and a transportation package in 2005.

“Freight mobility is key to economic vitality,” said Eide, who said drivers no longer need to play “Federal Way Roulette” when exiting or merging onto the freeway.

Approximately 3,600 freight trucks use Highway 18 to access Interstate 5 daily, according to WSDOT.

“They were a nightmare for trucks and cars,” said Stan Vander Pol, president of Peninsula Truck Lines Inc., of the interchange’s formerly outdated cloverleaf model that was built in the 1960s.

Vander Pol said the project will improve the economy through more efficient traffic flow. Trucks traveling from Eastern Washington to the Port of Tacoma, for example, rely on the interchange when shipping goods. The new flyover ramps allow the trucks — along with cars —  to maintain their speed and ultimately save fuel.

The project will help businesses like Wild Waves Theme Park, which is a cornerstone in Federal Way’s economy. Wild Waves attracts hundreds of thousands of visitors each season. The new ramps will improve access to the theme park while reducing the long lines of traffic that back up on Enchanted Parkway South.

As for the environmental impact of construction, WSDOT officials said the project included the planting of 11,000 new trees and 48,000 shrubs.

Map of the project: