COLUMBIA, Mo. - The biggest road project in Columbia is nearing completion.
The Stadium Boulevard and Interstate 70 interchange will close Friday evening for the weekend to finish a multimillion-dollar, months-long makeover.
The intersection will turn into a so-called diverging diamond interchange, which the Missouri Department of Transportation said will make the road faster and safer. Officials also said the design is the cheapest way to renovate.
In a special report, ABC 17's Evan Millward dug into those claims and traveled to the nation's first diverging diamond interchange to see how people who drive it every day like it.
The first such interchange was implemented in Springfield, Mo. at the intersection of I-44 and the Kansas Expressway.
Don Saiko, the project manager of Springfield's diverging diamond, and MoDOT Central District traffic engineer Joe Rickman are now helping 38 other states and Australia to help build the interchanges.
"Nobody wanted to be the first to try it, but we did it and it worked and now they're taking off everywhere," said Saiko.
Part of the popularity is that the interchanges are cheap to construct. To rebuild the entire Springfield bridge would have cost $15 million. The diverging diamond saved about 80 percent of that.
In Columbia, the city, state and taxpayers will pay about $3.5 million for the interchange, which is part of a nearly $13 million redevelopment of Stadium Boulevard in west Columbia.
The diverging diamond interchange is unlike any traffic pattern in Mid-Missouri and involves cars crossing over to the opposite side of the road.
"I think the public, they're a little nervous, they think they're on the wrong side of the road," said Saiko.
Drivers are on the wrong side of the road -- for at least a minute -- then pass through a traffic light and crossover to the right side of the road.
"I just tell folks, relax, follow the stripes, follow our signs, don't panic and let that 'I'm on the wrong side of the road' feeling get you in trouble, because that's really the only way you can mess up," said Rickman.
MoDOT said the interchange is safer because there are no longer left turns into oncoming traffic.
"A lot of the severe accidents were caused when you're trying to turn left on the interstate," said Saiko. "We eliminated that. You're not turning in front of traffic anymore."
Numbers from Springfield officials show in the first three years the diverging diamond was open, the number of crashes dropped.
"The only thing we've seen any kind of an increase in is side swipes, you know, people rubbing fenders a little bit, but I'll take that," said Rickman. "Those are not typically injury crashes."
However, the design was born out of a need to move more traffic more quickly.
"We used to experience 30 minute, 40 minutes or more delay to get people through just to get into the interchange to get into town," said Rickman.
When Millward asked Springfield drivers how they felt about the interchange, travel time topped the list.
"I think it's awesome," said one driver. "Before, you'd have to wait a long time at the beginning of this Kansas Expressway because you'd have to wait for this traffic and this traffic and this way we're all going the same way."
But, not everyone was as enthusiastic.
"It moves faster, but other than that, it's kinda confusing," said another driver. "It flows faster."
"I think it's crazy," said a driver.
Experts said following the flow is easy.
"Don't undersell it before you drive it, keep your mind open, pay attention to what you're doing, follow the signs and the stripes, follow the signals and you'll be fine," said Rickman.
The Stadium Blvd. bridge over I-70 will close to all traffic Friday at 7 p.m. and remain closed through the weekend. When it reopens by Monday morning, the interchange will look much different.
The project is not done, though. MoDOT still needs to widen Stadium Blvd. south to Broadway and add sidewalks and signals. Those projects will take about another year to complete.MoDOT Diamond Interchange Video