Detroit’s QLine streetcar will begin charging passengers for rides in 40 days, and the transit system’s organizers are racing to improve service and ease an expected ridership decline once people have to pay.

The streetcar has slowly added riders, and a potentially confusing fare payment system could jeopardize that growth.

Excluding its enormous opening weekend beginning May 12, the $187 million, 6.6-mile Woodward Avenue streetcar line has subsequently averaged 4,800 riders a day — up from initial estimates of 3,300 to 4,000 passengers a day for its first month. Since June 12, the system has averaged 5,150 riders a day, Qline spokesman Dan Lijana said.

A report issued by the QLine on Friday that says it averaged 6,300 passengers a day during the week of July 12. Those are the most recent numbers available as gathered by the line’s measuring equipment, which began taking more calibrated measurements after the system’s first month.

Rides have been free since service began May 12, and gratis service has been extended twice as organizers worked out kinks such as slow wait times between stations that have fueled user outcry.

The subsequent ridership growth is due to Detroit Tigers game crowds and other downtown events, improved service and regularly running five streetcars instead of four, Lijana said.

However, QLine officials expect a drop in ridership when paid fare service begins Sept. 4, but they expect it to recover and reach their budgetary goal of a 5,000-per-day average by the end of 12 months. After five years, the budget calls for an 8,000 rider per day average.

“Every system across the country sees some decline when they make a transition (to paid fares),” Lijana said, adding that the system’s backers still have to gather data on how ridership will be affected by bad weather.

To combat the expected decline, the QLine plans more passenger education, additional ticketing locations aside from its on-platform kiosks, and continued work on improving streetcar travel-time efficiency.

“We are well positioned to begin revenue operations in September,” Matt Cullen, CEO of the nonprofit M-1 Rail, which oversees the QLine, said in a statement. “Our service continues to improve and our customers are becoming more familiar with engaging with this new mode of transit.”

Ridership is expected to increase over time not only with improved service, but also because the new Little Caesars Arena will open alongside the streetcar line in September and it will have more have 150 to 200 events a year that include Detroit Red Wings and Pistons games. Other forthcoming downtown and Midtown residential, office, and retail projects are also expected by QLine officials to add the streetcar’s potential ridership.

Officials said they continue to improve the accuracy of expected streetcar arrival times displayed at each station, which are equipped with digital information screens. A common passenger complaint on social media has been long wait times between trains, and inaccurate arrival estimates at the station kiosks, and QLine officials said the system will be further improve accuracy.

The Detroit Free Press went as far on July 6 to publish a story in which staffers attempted to reach destinations faster than the streetcar by driving, biking, taking a bus, an Uber, and walking.

“We’ve worked with our operational partner Transdev to implement policies that will ensure streetcars arrive at consistent 15-minute intervals during peak service,” M-1 Rail COO Paul Childs said in a statement. “We’re pleased to see that wait times have decreased by 20 percent since the start of operations and 12 percent over the past month. We expect to see continuous improvements between now and Labor Day.”

Lombard, Ill.-based transportation management firm Transdev Services Inc. is the QLine’s the system’s third-party operator under a five-year, $15.5 million contract signed in January 2016.

The basic QLine passenger fare is $1.50, and QLine officials said they expect to build a base of monthly and yearly fare card users who will provide steady revenue and ridership numbers.

Additionally, the plan of using credit card-only fare kiosks at the 20 QLine stations, and cash-only kiosks aboard the streetcars, will be bolstered by still-developing plan to have fare kiosks at high-traffic locations near the line — including possibly One Campus Martius (formerly the Compuware Building) and Wayne State University. Passengers also will be encouraged to use the QLine mobile app to avoid lines at the kiosks, officials said.

QLine “street teams” will be deployed at stations and on the streetcars once fare service begins to help passengers understand how the system works, Lijana said.

A number of efforts have already been in the works to improve train times, officials said.

The QLine worked with the city and Michigan Department of Transportation to “optimize traffic signal timing at the intersections of Burroughs, Montcalm and Campus Martius.” Additionally, a streetcar approaching Congress Street at the 3.3-mile route’s southern terminus triggers a signal change.

Another time-saving measure is an operational policy change: The streetcars no longer stop at every station unless passengers are waiting to board or exit. Passengers push a button to initiate a stop.

Also saving time is improved battery service by the electric-powered streetcars. The streetcar system is now running 80 percent on battery power rather than on the aerial power lines, according to the report. The improved battery efficiency reduces the time the cars are stopped for charging, QLine officials said.

As part of the effort to keep the streetcars moving on schedule, city transit police have towed seven cars and issued 30 tickets for vehicles blocking QLine tracks, according to Thursday’s report.

On the personnel front, Transdev has hired four more drivers, bringing the total to 21 for the fleet of six streetcars. The line uses five cars from 10 a.m. to 7 p.m. Monday through Saturday. Six more drivers will be added by the start of fare service, the QLine said.

“Over the past month, we’ve increased QLine service, putting more streetcars on the road, reducing wait times between vehicles and integrated rider feedback into our operational improvement plan,” Cullen said. “The extended free ride period has enabled many more people to experience the QLine for the first time and helped Detroiters integrate the streetcar system into their daily travel.”

The Troy-based Kresge Foundation, which contributed $50 million to the $187 million it took to build the streetcar line over three years, covered the fare costs beginning July 1 through Labor Day. The foundation said it was covering the fares, estimated at a cost of a few hundred thousand dollars, to allow the system’s backers time to solve the streetcar’s teething problems and build ridership.

“We believe this decision will support the QLine’s long-term success and position the streetcar as a successful demonstration project for transit in the region,” said Kresge President and CEO Rip Rapson in a statement.

QLine officials said paid passenger service will begin Sept. 4 barring a major disruption.

The system, which took 10 years of planning, financing and construction, has run largely without incident. One streetcar suffered minor cosmetic damage on July 24 when it was struck by a car making an illegal turn. No one was injured, but the streetcar was briefly taken out of service for repairs.

Fares are part of the revenue mix, along with the sale of the line’s naming rights and corporate advertising at the stations, that fund the line’s estimated $6 million-plus annual operational costs.

M-1 Rail officials have always intended to turn the system over to a public regional transit agency to operate and fund, but a dedicated funding source has yet to be established. Until a tax is approved to sustain the line long term, Cullen has said other operational funding options included seeking more corporate donations, selling more advertising, and reselling the naming rights.

The QLine’s construction costs and several years of operational money were funded by a mix of public and private sources.