PHOENIX >> Campaigning over the future of mass rail transit in Phoenix heated up today over next week’s special election asking voters whether to halt all expansion of the light rail system in the nation’s fifth largest city.

Several dozen college students and recent graduates gathered briefly in the afternoon along the line downtown, waving signs that called for a “no” vote on the light rail measure. “Extend our rail and extend our future,” one sign said.

“It’s so much easier to take the light rail than the bus,” said Trinity Miracle, 18, a student at Arizona State University who has depended on the train since high school.

Shelley Jackson, 23, who recently graduated from ASU, said the planned extension of the rail into her old south Phoenix neighborhood would create educational and job opportunities for young people. Still, she acknowledged that “a lot of people do worry about gentrification.”

Arizona election watchers say a large number of early mail-in ballots points to higher than expected voter turnout for the Aug. 27 balloting at the height of Phoenix summer, when many people leave town to escape triple-digit temperatures. Between 88% and 97% of all ballots cast at the last three citywide elections were cast by early ballot, the City Clerk’s office says.

The clerk received around 123,350 completed ballots by Monday, said spokesman Matthew Hamada. That’s about 22% of the 549,128 early ballots mailed to voters who requested them, and 16% of the city’s 764,653 registered voters.

“Turnout appears to be heading in the direction of around 25%,” Arizona elections data wonk Garrett Archer said Monday on his Twitter account, The AZ Data Guru . The former data analyst for Arizona’s secretary of state was a must-follow during last November’s mid-term elections. He now works for local network television affiliate ABC15 .

The turnout by Phoenix voters was 20.8% on Aug. 25, 2015, when they weighed in on Proposition 104, a plan approving a tax increase to pay for transportation projects over 35 years, including the light rail. The final vote was about 54.7% for the increase and 45.2% against it, according to the city clerk’s website.

Proposition 105 was placed on this month’s ballot after a signature-gathering drive by opponents of a planned 5.5-mile (8.85-kilometer) extension of the rail into south Phoenix. If passed, the measure would stop that and any other expansion.

Now stretching more than 26.3 miles (42.3 kilometers), construction of the Valley Metro light rail system began in March 2005 and it began service in December 2008. The agency says in 2016, the system served 15.6 million riders, with an average weekday ridership of about 48,000.

The rail is used during the week by high school and college students and working professionals, as well as disabled and elderly people who find bus travel difficult. Rail critics point out the system is also heavily used by homeless people.

A second measure, Proposition 106, aims to limit the city’s spending until its pension debt is significantly reduced.

But the rail measure is getting the most attention.

A group called Building a Better Phoenix organized the initiative effort. Its supporters include business owners along the planned south Phoenix extension route and City Council members Sal DiCiccio and Jim Waring.

“Fixing roads and sidewalks, expanding bus and dial-a-ride service and other public improvements that improve our quality of life should come first!” reads a Building A Better Phoenix mailer.

Phoenix Mayor Kate Gallego and the other council members oppose the measure, saying the rail system would lose millions of dollars in federal funds that cannot be used for other purposes, including a recently announced $100 million grant from the U.S. Department of Transportation.

The Greater Phoenix Chamber of Commerce, the Arizona Hispanic Chamber of Commerce, the United Phoenix Firefighters, the Arizona AFL-CIO, and the local AARP chapter oppose Proposition 105 as well.

Those groups also oppose Proposition 106, saying it could slash funding for libraries and other city services such as public swimming pools and community centers.

“Protect light rail, protect our community,” reads a mailer urging a “no” vote on both measures.

Along with voting by mail, city voters can cast ballots in person over three days. More information is on the clerk’s website .