Federal Court: Wisconsin DOT's Traffic Projections Fail to Justify Highway Expansion

A federal court found that the Wisconsin DOT uses specious traffic projections to justify the $146 million widening of Highway 23. The state must now either perform verifiable forecasting or scrap the expansion plans.

2 minute read

May 28, 2015, 6:00 AM PDT

By Todd Litman


State departments of transportation all over the country use specious traffic projections to justify hugely expensive road widening projects. That’s how you end up with the graph below—showing how DOTs continued to forecast traffic growth year after year, even as driving stagnated.

Aggregate traffic projections from the nation’s state and regional transportation agencies have become increasingly divorced from reality. (Source: SSTI)

Wisconsin DOT is perhaps the most notorious manipulator of traffic forecasts. Fortunately, Wisconsin also has a strong network of organizations holding the DOT's feet to the fire and dragging it to court if need be.

Today, 1,000 Friends of Wisconsin Executive Director Steve Hiniker shares news of a major legal victory. A federal court sided with the organization in a suit against WisDOT that challenged the traffic data used to justify the $146 million widening of Highway 23:

According to the ruling, the Wisconsin DOT failed to justify the amount of traffic it projected as likely to use the road in the future. The Court ruled that the project is ineligible for federal funding until documented accurate traffic forecasts can be made that justify expanding the highway. The state can now either go back to the drawing board and do verifiable forecasting or scrap the expansion plans. The ruling does not stop the state from building the project using only state funds.

“We encourage the DOT to immediately make safety improvements along Highway 23 that could always have been done without expanding the highway to 4 lanes,” added Hiniker.

“We call on the legislature to stop funding any road expansion project that has not already begun construction until updated, accurate and verifiable traffic forecasts can be made. The state cannot afford to spend billions of dollars on highway projects that are not justified by accurate data,” concluded Hiniker.

This case could have dramatic ramifications for other highway building plans in the state. Critics of DOT building plans have questioned a number of projects based on faulty traffic projections – including the proposed almost billion dollar expansion of the I-94 corridor near Miller Park in Milwaukee.

Wednesday, May 27, 2015 in Streetsblog Network

Young Professional

I love the variety of courses, many practical, and all richly illustrated. They have inspired many ideas that I've applied in practice, and in my own teaching. Mary G., Urban and Environmental Planner

I love the variety of courses, many practical, and all richly illustrated. They have inspired many ideas that I've applied in practice, and in my own teaching.

Mary G., Urban and Environmental Planner

Get top-rated, practical training for planners

"Planetizen federal action tracker" logo superimposed over black and white image of US Capitol dome.

Planetizen Federal Action Tracker

A weekly monitor of how Trump’s orders and actions are impacting planners and planning in America.

September 23, 2026 - Zachary Whalen

Passengers board an Amtrak train under a cloudy sky.

Amtrak, CN end decades-long dispute with eight-year agreement

The new operating agreement establishes an updated framework for the companies to work together, including processes to resolve disputes.

September 18, 2026 - Mass Transit

An Airo train driving towards the camera on a track. There is a forest behind it.

Northwest rail fans eager for Sept. 30 debut of Amtrak’s Airo fleet

Get ready for that new train smell and more seats. But they won’t go faster or run more frequently on the Cascades route in Washington and Oregon.

September 22, 2026 - Washington State Standard

The outside of a brightline transit hub with many windows on a sunny day.

Brightline Florida files for bankruptcy

The transit company is over $5 billion in debt.

September 26 - Financial Times

A blue Metrolink train with two cars drives toward the camera.

St. Louis Metro to test if single-car trains can reduce operating costs, maintain rider satisfaction

The pilot program will run from October to spring 2027, and begin with one single-car train operating on Metrolink’s Red and Blue lines.

September 25 - Mass Transit

An abandoned mine in Pennsylvania. The ceiling is low, the walls and floors are gray, and mine cart tracks run along the bottom.

Pennsylvania is building data centers in abandoned mines

Housing data centers in mines provides an alternative to destroying local forests and may spare residents from data centers’ noise and air pollution.

September 25 - Inside Climate News

FREE Course: Walkable City 1: Why Walkability?

After describing his path towards focusing on walkability as the essence of good planning, Jeff Speck marches through his five principal reasons for making more walkable places.

Reinventing Malls: Planning Alchemy—Turning Gray Fields Into Gold

The course focuses on the opportunities and imperatives that shape reinvention of mall sites.

Senior Planner

City of Thousand Oaks

Community Development Director

City of Wisconsin Rapids

Professor of Urban Planning

Harvard University Graduate School of Design