Traffic is only part of the story. What is WisDOT missing?

We attended the public meetings for WisDOT’s Lake Interchange last month and have some takeaways from the presentation materials.

After this round of meetings, it’s clear to us that WisDOT’s traffic study is constrained in part by the traffic model limitations, including pedestrian & bicycle infrastructure, and the incomplete or conservative transit expansion data and land-use assumptions. The flaw with current traffic modeling is that they're highly sensitive to the assumptions used and can shape skewed analyses across other areas outlined in the study purpose and need.

The study's sensitivity analysis predicts changes in car dependency based on various assumptions: including public transit investments, land-use changes, population growth, and vehicle occupancy (whether or not people will carpool). These assumptions influence how dependent people are on driving. In general, car-dependency change is not particularly intuitive, but the idea is that if transit access improves, there are more transportation options, or neighborhoods become denser, people may choose to drive less often.

Since multimodal transportation and land-use are some major categories emphasized in the removal alternative, we looked more closely at how the study accounts for future investment and development patterns.

Transit investment

The study utilizes Southeast Wisconsin Regional Planning Commission's (SEWRPC) updated VISION 2050 plan. VISION 2050 includes recommendations for bus and rail transit service improvements as well as what’s possible under a Fiscally Constrained Transportation System (i.e. what portion of the system can be funded without a dedicated transit funding source).

However, the plan does not yet include updated recommendations or service scenarios from the MARK Rail Study, which is exploring the potential for establishing passenger rail connections between Milwaukee, Racine, and Kenosha, including intermediate stops between the cities. Additionally, it's unclear how intercity rail service (Amtrak) is accounted for in the analysis, as VISION 2050 doesn't explicitly provide recommendations for enhanced intercity rail service, including the Hiawatha line nor the proposed extension to Madison. Side note: The Hiawatha line has the highest ridership of any Amtrak service outside the East and West Coasts.

Since the study doesn’t fully incorporate these multimodal scenarios and investments into its traffic modeling, it may overestimate how many car trips continue to drive through downtown in a removal scenario. Therefore, the study may also be overstating how much the traffic from the freeway will shift onto local streets, even with a more multimodal transportation network. If the up-to-date transit investment assumptions were incorporated, the model may project different outcomes for vehicle trips to and from downtown, mode shift in the long term, and regional travel patterns.

Further, regional planning analysis from SEWRPC has found that the Milwaukee County Transit System generates substantial value to the regional economy, including reduced congestion, lower vehicle operating costs, reduced crashes, and reduced emissions. These benefits reach more than the transit riders and contribute to the efficiency of the region's overall transportation system. The magnitude and effectiveness of transit investments would influence regional mode share and congestion outcomes.

Photo: Buses on Bikes - MCTS

Land-use Changes

WisDOT uses the assumption that 15% of existing downtown office space converts to apartments as their measure for land-use changes and therefore changes in car dependency. However, at the meetings, a few boards presented SB Friedman’s market and land-use prediction, including “1,400 residential units, 970 hotel rooms, and 800,000 SF of office” as well as a projection for 14,000+ new residents living downtown by 2050. 

This type of change in land use can affect the types of trips made in the area, how long the trips are, and the mode used to take the trip (walk, bike, transit, and driving). If land-use change is underestimated in the analysis (e.g. relying on the 15% office conversion assumption), it may overestimate the number of trips made in cars and therefore produce higher congestion forecasts.

We’ve seen traffic forecasts from WisDOT in the past that assumed higher vehicle volumes than what ultimately occurred after removal. When the Park East Freeway was up, the corridor carried around 22,000 vehicles per day. Early WisDOT and SEWRPC forecasts estimated 28,000 – 35,000 vehicles per day if Park East were to come down. Today, McKinley Ave./Knapp St. sees about 16,250 vehicles per day on average. 

Photos: Park East Freeway Before and After Removal - City of Milwaukee Department of City Development

Not to mention, the corridor has also experienced significant reinvestment and development after removal; over $1.06 billion in private development since it was removed. It would be useful to see how SB Friedman’s predictions influence the assumptions for traffic modeling, especially whether their updated density and development predictions are fully reflected in the mode shift, trip generation, and resulting traffic volume forecasts.

Choosing freeway removal and replacing it a with a boulevard is visionary, but it's not as unattainable as you'd think.

Sources:

• Amendment to the Regional Transportation Plan - 2020 Park East Freeway Corridor - SEWRPC

• Economic Development and Highway Right-Sizing Case Studies - FHWA

• Wisconsin Department of Transportation Chicago - Milwaukee Intercity Passenger Rail Corridor - Facts

• Park East Redevelopment

• VISION 2050 - 2024 Update - Updates to VISION 2050 Recommendations