What is the I-65/I-70 North Split Project (North Split Project)?

The North Split Project includes an upgrade of the existing interchange where I-65 and I-70 meet on the northeast side of downtown Indianapolis. The North Split is the second-most heavily traveled interchange in Indiana. Bridges in the interchange area require rehabilitation or replacement due to their poor structural condition. The North Split Project will also provide the opportunity to improve operations and efficiency for all users.

INDOT recently began work on an Environmental Assessment (EA), as required by the National Environmental Policy Act (NEPA). INDOT is about six months into the two-year NEPA process. As this NEPA study is prepared, INDOT will conduct a robust public outreach program.

Why is this happening now?

Portions of the North Split interchange were built 50 years ago. The interchange is operating at full capacity and is at the end of its useful life. Specifically:

  • 32 bridges in the area need rehabilitation or replacement due to poor structural conditions
  • Deteriorating pavement requires constant repair and patching on the roadway and shoulders, which is expensive and disruptive for users
  • The current North Split interchange has many complex lane change configurations that create “weaving” conflicts as motorists cross paths to reach their destination. Weaving movements with high volumes of traffic are a major cause of congestion and reduced safety on interstates

What is the purpose of the North Split Project?

The purpose of the North Split Project is to provide an improved transportation system leading to and through the I-65/I-70 North Split interchange in downtown Indianapolis.

What needs must the project meet?

The North Split Project must meet the following transportation needs:

  • Correct deteriorated bridge conditions
  • Correct deteriorated pavement conditions
  • Improve interchange operations
  • Reduce traffic congestion
  • Improve safety

How can the project benefit drivers that use the interchange?

About 214,000 vehicles use the North Split interchange each day. It is operating at full capacity and traffic regularly slows or stops during peak travel times. As the major bridge work is underway, ramps can be reconfigured to minimize conflicts and reduce the number of lane changes drivers must make. Replacing the existing deteriorated infrastructure and adding capacity will ensure the interchange operates at current design standards through 2040. This will decrease congestion and improve operations and efficiency for all motorists in this busy area.

What project activities are currently underway?

INDOT recently published the System-Level Analysis, which will help guide the scope of the North Split Project and informs current public dialogue regarding the interstate system in downtown Indianapolis.

Public feedback is being collected through June 7.

How did INDOT decide to move forward on the North Split Project?

The need for the project was defined in the Project Intent Report, a planning level document developed with preliminary data. It identified the North Split interchange is functioning well below acceptable levels of service now and many portions are past their life expectancy. The report did not include a preferred alternative, final design, or project limits; those are being developed now through an Environmental Assessment as part of the NEPA process.

What options are currently being studied?

The following concepts were analyzed in the System-Level Analysis:

  • No-Build (maintain existing configurations)
  • Transportation System Management (TSM)
  • Upgrade existing interstates, including the North Split
  • Depress downtown interstate(s)*
  • Replace interstate sections with boulevard(s)*
  • Construct surface boulevard(s) + interstates in tunnel(s)*
  • Construct new interstate link(s)
    * Suggested by community groups

What criteria were used to screen the concepts? How are these criteria ranked?

The concepts were reviewed based on performance, costs and impacts, but no rankings were provided. Click here to see the System-Level Analysis comparison chart.

The North Split interchange was closed during Hyperfix and that worked fine. Why can’t we just close the interchange and remove the interstates?

Approximately 265,000 vehicles enter or pass through the downtown area via interstates each day. Removing or reducing the capacity of downtown interstates would cause much of this traffic to divert to local streets. This was actually demonstrated during Hyperfix according to a study conducted by Purdue University in 2003.

During Hyperfix, the segment of I-65/I-70 between the North and South Split interchanges was closed for 55 days for road/bridge construction. This was not a total interchange closure. The downtown exits from I-70 westbound and I-65 southbound remained open. According to Table 25 of the Purdue report cited above, daily traffic impacts to local streets during Hyperfix included the following:

  • Pennsylvania Street, (Fall Creek to Washington) – 46 percent more traffic
  • Delaware Street (Washington to Fall Creek) – 112 percent more traffic
  • Fall Creek/Binford (Illinois to 56th) – 35 percent more traffic
  • College Avenue (Washington to 10th) – 195 percent more traffic
  • East Street (10th to Washington) – 75 percent more traffic
  • Martin Luther King Street (16th to I-65) – 36 percent more traffic
  • West Street (I-65 to I-70) – 78 percent more traffic

Isn’t most traffic on I-65 and I-70 just going through the city? Why can’t INDOT reroute this traffic to I-465?

Less than 10 percent of the traffic on downtown interstates during peak periods is through traffic, meaning most of the travel on I-65 and I-70 begins or ends inside I-465. This is especially true during peak periods, when the interstates are heavily used for home-to-work travel. Peak hour traffic volumes approaching downtown from I-70 east in the morning are the highest in the state. Traffic volumes leaving downtown on interstates in the morning is much smaller. During the morning peak, about 65 percent of the traffic on I-70 east and about 70 percent of the traffic on I-65 south is inbound towards downtown. This pattern is reversed in the evening. Most of these trips are not through trips. They would not divert to I-465.

What are the construction impacts of potential alternatives?

According to an Independent Feasibility Study, the estimated construction time to replace 1.6 miles of I-81 in Syracuse, New York with a tunnel and boulevard is around 9 years. (The north leg of the Indianapolis inner loop is about 1.5 miles long, and the entire downtown system is about 5 miles long.) Trips served every day by downtown interstates must be accommodated as future systems are constructed.

What are the costs of concepts in the System-Level Analysis?

The following are the estimated costs for the concepts reviewed in the System-Level Analysis:

  • No-build: No change
  • Transportation Systems Management: N/A
  • Upgrade existing interstates: $900 million to $1.6 billion
  • Depress downtown interstates: $1.5 billion to $2.4 billion
  • Boulevards to replace interstates: $500 million to $900 million
  • Boulevards and tunnels: $3.3 billion to $5.5 billion
  • West St. interstate tunnel and boulevard: $1.6 billion to $2.6 billion

Cost ranges are included due to uncertainties at this conceptual stage.

The preliminary cost estimate for the North Split Project was around $250 to $300 million.

Some residents believe INDOT did not do its due diligence in determining the scope and use of innovative alternatives – such as boulevards or tunneling the interstate – for the North Split Project. Has the design alternative already been selected?

INDOT is following the NEPA process. It is not unusual for new alternatives to be identified as part of this process. In the System-Level Analysis, INDOT investigated many concepts, including the proposal from local community groups that includes ideas like boulevards and tunneling.

Based on the results of the System-Level Analysis and the current condition of the North Split interchange, INDOT must move forward to make much-needed repairs to improve safety.

How can I learn more about the alternative concepts being that were considered in the System-Level Analysis?

The System-Level Analysis is available here.

The project team is available to meet with individuals who are interested in learning more about this project – residents, community leaders, neighborhood groups, civic organizations, etc. Interested parties are encouraged to reach out to Emily Kibling at info@northsplit.com to schedule a meeting.