|WALLY route map|
Trains would run daily over existing trackage owned by the Great Lakes Central Railroad, which has also committed to providing ten stainless-steel bi-level passenger cars. The service is proposed as an alternative to adding a third lane to U.S. Highway 23 (US 23), which would cost upwards of $500 million. The Ann Arbor Area Transportation Authority is the "designated authority" for the project.
Initial start-up costs were projected at $2.9 million, with annual operating costs at $4.8 million. Backers of the project estimate 884,000 riders per year, with a fare revenue of $2.4 million. The remainder would be subsidized by state and local governments. The project has received funding commitments from the Michigan Department of Transportation, the Ann Arbor Downtown Development Authority, and the Northfield Township Downtown Development Authority. Attempts to obtain a $1 million grant from the Federal government fell through. Both the University of Michigan and the Ann Arbor offices of the Environmental Protection Agency would pay the fares of any employees who took the train in lieu of commuting. Backers conducted a $150,000 feasibility study of the line, with money pledged by the University of Michigan, the Great Lakes Central Railroad, the Southeast Michigan Council of Governments (SEMCOG), Washtenaw and Livingston Counties. The study reported back that the project is viable, but placed start-up costs at $32.4 million, much higher than initial estimates. Most of the outlay would be for infrastructure improvements. After three years of service the line would become eligible for federal transportation funding.
In April 2010 supporters announced a scaled-back proposal with start-up costs of $16–$20 million, with yearly operating costs of $7.1 million. As of September 2011, $16 million had been spent on capital costs with another projected $19 million required for startup, and operating costs were projected as an annual $5.4 million. In his oral update  to the AATA board on January 19, 2012, AATA CEO Michael Ford reported on WALLY, the north-south commuter rail project that would connect Howell and Ann Arbor. Ford stressed that it’s currently not a viable project without the TIGER III funding that had been hoped for (but not received).
In October 2014, a new study into commuter rail service began. Expected to take about 18 months, it will focus on more detailed operational aspects of possible service than the 2008 study, including ridership, costs, station and maintenance locations, and funding. It will also examine possible alternatives to rail service, such as busses or additional highway lanes. The study is funded primarily through a Transportation and Community System Preservation grant, jointly administered by the Federal Highway Administration and the Federal Transit Administration, as well as a 20% match from the Ann Arbor Area Transportation Authority.
The proposed end-points of the line are Ann Arbor and Howell, for a total length of 27 miles (43 km). The line is operated by the Great Lakes Central Railroad, a short line railroad who leases the track from CSX, and was originally built by the Lansing, Alma, Mt. Pleasant & Northern and the Toledo, Ann Arbor & North Michigan, forerunners of the Ann Arbor Railroad, between 1885 and 1895. Proposed intermediate stops include Brighton, Hamburg and Whitmore Lake. The stop in Brighton would not be in the downtown but rather at Chilson Road, four miles (6.4 km) to the west, as the railroad line through the downtown is owned by CSX directly and no operating agreement has been reached. Also pending is an arrangement with the Ann Arbor Railroad for service over the last 1.75 miles (2.82 km) into Ann Arbor itself. Trains in Ann Arbor would stop on Plymouth Road near the North Campus of the University of Michigan and would neither cross the Huron River nor interchange directly with Amtrak.
- "Washtenaw Livingston Rail Line (WALLY or WaLi) Technical review; Scope of Services". Washtenaw County. February 20, 2008. Retrieved March 24, 2008.
- "Rail Cheaper for Commuters, Study Says; But Fares Wouldn't Cover Costs; Subsidies Needed, Experts Warn". Ann Arbor News. October 21, 2007.
- Shea, Bill (October 29, 2008). "Ann Arbor–Howell Commuter Rail Line Chugs Ahead; Authority Named". Crain's Detroit Business. Retrieved October 31, 2008.
- "Grant Denied, but Rail Effort on Track". Ann Arbor News. October 26, 2007.
- Olander, Valerie (March 24, 2008). "County Studying Commuter Line: Officials Want to Know How Much the Rail Service to Ann Arbor Will Cost Livingston County". The Detroit News. Retrieved March 24, 2008.
- Karol, Kristofer (April 16, 2008). "Commuter Train Study Wins Fiscal Go-Ahead". Livingston County Daily Press & Argus. Retrieved April 16, 2008.
- Olander, Valerie (July 7, 2008). "Study Calls Ann Arbor–Howell Commuter Rail Line Viable: But Startup Costs Expected to Far Exceed $32.4 Million Estimate". The Detroit News. Retrieved July 7, 2008.
- "County Hesitates on Rail Idea: Board Requests Viability Study Before Committing Money". Ann Arbor News. December 28, 2007.
- Gershman, Dave (April 26, 2010). "WALLY Isn't Dead but Needs $10 Million More for Demonstration Rail Service, Officials Say". AnnArbor.com. Retrieved April 27, 2010.
- "WALLY Commuter Rail Status Report" (PDF) (Draft report). September 2011.
- "AATA in Transition, Briefed on State’s Plans". The Ann Arbor Chronicle. January 21, 2012. Retrieved January 30, 2012.
- "Commuter Service Again Studied Along Ann Arbor Railroad". Trains Magazine. October 27, 2014. Retrieved October 28, 2014.
- Meints, Graydon M. (2005). Michigan Railroad Lines. East Lansing: Michigan State University Press. pp. 71–76. ISBN 0870136933.
- "Howell Votes to Support Regional Rail: EPA, U-M Commit to Pay Part of Riders' Costs". Ann Arbor News. June 15, 2007.
- Shea, Bill (September 10, 2007). "Proposed Rail Line Still Hasn't Left Station". Crain's Detroit Business. p. 12.