The SMART bus millage renewal passed by a razor-thin margin in Macomb County on Tuesday, while easily passing in Oakland and Wayne counties, according to unofficial results.

With 100 percent of the county's 338 precincts reporting, the margin to renew the Suburban Mobility Authority for Regional Transportation's 1-mill property tax for four years was 77,502 (50 percent) in favor to 77,479 (50 percent) against.

It passed by wide margins in Wayne (75 percent) and Oakland (77 percent) counties. The tax is by communities that have opted into the bus system in those counties, but it is a countywide ballot measure in Macomb.

Failure would have ended SMART bus and other transit services in Macomb by the end of the year, and cause the layoff of some of its more than 800 staff.

Macomb is where anti-tax sentiment defeated a tax to fund a proposed new regional transit system, dooming that project.

The SMART property tax funds more than half of the suburban Detroit bus system's operating budget. It provides about 10 million rides for users in the three counties.

Four years ago, the Macomb County renewed the tax with nearly 60 percent of voters in favor.

A simple majority in each county was needed for the tax to continue for the next four years.

The tax will generate $70.5 million of SMART's $126.8 million fiscal 2019 budget, or nearly 56 percent of the system's funding. The remainder comes from fares, advertising, and state and federal sources.

There's been fear from public officials that the failed 2016 regional transit system tax, and subsequent talk of pushing for another such ballot question, could lead voters to reject the SMART tax renewal.

Macomb County Executive Mark Hackel, and his Oakland County counterpart, L. Brooks Patterson, advocated for the SMART tax renewal while previously opposing the 2016 regional transit tax that failed at the polls that year. They have since called for the regional transit authority, which oversees SMART and other transit systems, to be dismantled in favor of expanding SMART.

The bus tax was up for renewal in 26 communities in Wayne County and 24 communities in Oakland County that have opted into the suburban transit system. Oakland County has 33 communities that have opted out of SMART and Wayne County has 17 opt-out communities, including Detroit.

On the Oakland and Macomb ballots, the tax renewal was actually a request for a slight increase, from .9926 mills to 1 mill. Because of a Headlee amendment-mandated rollback in the rate since then, the tax rate had declined.

The 1-mill tax costs property owners $100 a year on a house worth $200,000. Renewing the tax to that 1-mill level increases that $100 by about 75 cents annually.

Voters originally passed the SMART operating tax in 1995 and it's been reauthorized in 1998, 2002, 2006, 2010, 2012 (Oakland county only) and 2014.

Mass transit has been an ongoing debate topic in the region for decades, with advocates for increased services saying that better publicly funded ways of moving people around will spur economic growth and better the lives of residents. Metro Detroit has a splintered system of primarily buses across several agencies that compete for resources and don't always cooperate.

SMART, created in 1967, provides bus service along 47 routes in Wayne, Oakland and Macomb counties.

It budgeted $12.7 million from fares this year, with most of that coming from its core fixed-route bus services.

About 840 people work for SMART. The bus agency in June warned that it would lay off up to all 840 if the funding issue failed. Under state law, Michigan employers are required to file WARN notices 60 days in advance of a layoff exceeding 100 employees.

SMART is forbidden by law from campaigning for a "yes" vote on ballot issues, and is limited to educational efforts only. There was no visible organized pro-tax campaign this year.

Opposition to the tax renewal came from the Michigan Taxpayers Alliance, a conservative group run by Macomb County Commissioner Leon Drolet.

He said Wednesday that he'll consider seeking a recount once the election result is certified in 14 days and if the vote remains then in favor of the renewal's passage.

"We'll have to wait and see," he said, adding that he expects SMART's backers to seek a recount if the certified results swing the results to rejection -- which can be possible during the certification process with a tiny margin.

— Crain's reporter Chad Livengood contributed to this story.