FAQs about the System-Level Analysis

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.