Exclusive: INDOT looks at 7 different ways to rethink Downtown Indy's North Split

The Indiana Department of Transportation heard the public's pleas to explore multiple options to improve the network of highways coursing through the north end of Downtown.

And, after about four months of studying traffic, the cost and impact of seven alternatives for the I-65/I-70 north split, INDOT plans to release its findings to the public Thursday.

"We took a step back and said, 'You know what, if this takes an extra couple months of research and modeling, we need to do that,'" INDOT Commissioner Joe McGuinness said. "Let's not just force a project on everyone, let's really take a look and hear them out."

Campus captive: Trafficking victim says she was enslaved on Indiana University campus

Don't touch: Armored Brinks truck sends cash flying on I-70

Last fall, INDOT announced the need to rebuild the split, which is where I-65 and I-70 meet on the city's north side, south of 16th Street, east of College Avenue, stretching south through Fletcher Place. The decaying network of highways and 32 bridges transport more than 160,000 cars daily. INDOT estimated the cost to rebuild the north split to be $250 to $300 million.

The public wanted INDOT to approach project more imaginatively than just rebuilding what already exists. They proposed ideas such as moving the highways underground and removing the interstate altogether and put boulevards in their place.

In March, a group of neighborhoods, businesses, civic organizations and private citizens created a coalition — Rethink 65/70 — out of a concern about what they called the lack of transparency from INDOT on its initial plan.

When the highways were first built, they divided Downtown and the eight surrounding historic neighborhoods and pushed noise, pollution and traffic into the center of city. Rebuilding would just continue the damage caused decades ago, this group believes.

Time is running out to fix the issues, McGuiness said. Beyond deteriorating roadways, there have been 1,600 crashes at the north split between 2012 and 2016, largely rear-ends or sideswipes. Both types of accidents usually occur with too much traffic or complicated traffic patterns not meant to hold the volume of cars driving on it daily.

"We have a safety issue that we need to address," he said. "The crash data speaks for itself. I don't think it's any secret that the north split finds its way into traffic reports. We can't run out the clock and just allow it to do something naturally."

Seven options were considered, and two were eliminated due to a lack of feasibility, said Kia Gillette, environmental project manager for HNTB, a construction and infrastructure consulting firm and one of the north split project leads.

More about the north split: What you need to know about the I-65/I-70 north split controversy

A massive job: Rebuilding the I-65/I-70 north split is 'bigger than Lucas Oil Stadium'

Option one is to maintain the existing system, patching and repairing as needed and not building anything. Something has to change, though, because the 32 bridges are in disrepair.

"One third of them have five years or less of useful life left," Gillette said.

Chunks of concrete have been reported falling on cars; patching the cracks only acts as a temporary fix, Gillette said.

"We don't think that's a viable option," she said.

The second option is to find a way to divert traffic from the split to I-465 or Indy's bus transit system.

As part of its research, INDOT input factors into a computer program designed to project traffic outcomes, and learned that just 10 percent of the traffic on the north split is through-traffic. This means at the most, INDOT could only divert about 16,000 cars daily.

"We were a little surprised that number was so low," she said. "The level of diversion would be really insignificant."

The remaining five options are still being considered, Gillette said.

Option three is to reconstruct the existing system as is. This would cost an estimated $900 million to $1.6 billion over five years, and would ease traffic by 10 percent during peak morning times and 6 percent less in peak evening times.

Option four is to move the interstate underground. This would also alleviate traffic by 10 percent during the peak morning and evening times and would cost an estimated $1.5 to $2.4 billion to construct over six years.

There are a lot of unknowns with the fourth option, though, Gillette said. If the tunnel is lower than the water table, INDOT would have to frequently pump water, which would increase costs. Soil quality and the possibility of underground utilities that would be costly to move are also unknown factors.

Option five would replace the highways with low-speed six-lane boulevards at street level. The boulevard option is cheaper than others, at an estimated $500 to $900 million to construct over four years. But, drivers would face more of a delay during peak traffic hours — 40 percent more in the mornings and 145 percent more at night — due to slower speeds.

A boulevard would accommodate a maximum of 50,000 cars daily, which is fewer than one-third of the average number of cars that go through that area. For perspective, about 38,000 cars travel on West Street and Washington Street daily, and 23,000 on Meridian Street at 38th Street.

With an overflow of anywhere from 59,000 to 111,000 cars daily, those drivers would flood Downtown streets, looking for an alternative route.

"The majority of that traffic would still have to get here somehow," Gillette said. "You're creating a difficult barrier to get through."

Option six is a combination of options four and five: Creating the same six-lane boulevards as option five to replace I-65 and I-70, and moving the highways underground at the north and south splits.

This option would cost $3.3 billion to $5.5 billion and take 10 years to construct. It would improve morning traffic delays by 9 percent, and decrease evening delays by 3 percent.

Option seven was created by a group of engineers thinking of all possible ideas, Gillette said. When the highways were built more than half a century ago, there was an intention to connect the west side of the Downtown inner loop where West Street is. This option would close that loop by building a tunnel under West Street, and through to the south split, while rebuilding the north side of the loop and West Street as six-lane boulevards.

The final option would could an estimated $1.6 to $2.6 billion and take seven years to construct, and cause a 23 to 24 percent delay in traffic during peak morning and evening times.

The seven options serve as potential long-term concepts for the entire Downtown interstate system, Gillette said, but don't replace the immediate need to replace the north split.

"We're looking at this as a way to inform what we do. Is there anything we found here that would tell us to do something different?" she said. "We've got to move forward with the north split project, but we're not eliminating any of these for the future."

INDOT will open the process to the public for feedback until June 7, then develop a detailed proposal which will begin to incorporate design elements. Construction wouldn't begin until at least 2020, she said.

"We're still very early in the process," she said.

Call IndyStar reporter Amy Bartner at (317) 444-6752. Follow her on Facebook, Twitter, and Instagram.