Cut off in traffic by a bus and then flipped off by its driver, Roger Watts filed a complaint with Metro Transit. Mark Jackson did the same thing after he endured a harrowing bus ride with “a very aggressive driver.”

A sharp rise in complaints about bus drivers has accompanied the recent jump in transit ridership. Metro Transit logged more than 6,111 complaints against bus drivers in 2012, up 30 percent from 4,686 filed five years ago. Last year, there was one complaint for every 11,431 rides, compared to one in 15,283 in 2008.

Metro Transit and bus driver’s union leaders explain the surge in gripes as a sign that it’s easier than ever to file a complaint, rather than indicating any problem with drivers. While the majority of complaints still come in by phone, agency officials say the complaints arrive by e-mail, text message, Twitter and Facebook, and through a portal on its website. In 2010, Metro Transit also installed a new system to better track complaints.

“Many of our riders are well connected,” said Brian Funk, Metro Transit’s assistant director of field operations. “They use mobile devices. That lends to instant connection. If they want to comment, good or bad, you have the ability to provide instant feedback.”

The most common complaints were that drivers left passengers stranded, left a stop early or arrived late, or did not follow the published route. Others said drivers were reckless, rude, chided the poor, berated the disabled, smoked on the bus and talked on cellphones while driving.

Jackson reported his driver after a recent trip on a Route 18 bus in which the driver was going “uncomfortably fast” down Nicollet Avenue.

“He had an aggressive attitude. He was sailing into bus stops and then he’d hit the brakes. The acceleration was the same way, very rapid,” Jackson said. “It was scary. I could not relax and read the newspaper. ... Our drivers are generally spectacular, but I had this feeling, my God, he’s going to kill somebody, and how would I feel if I didn’t file a complaint.”

Metro Transit said it did not have a record of Jackson’s complaint, so he refiled it last week. The agency said it is now looking into it.

Mark Lawson, the new president of Amalgamated Transit Union 1005, which represents 1,500 drivers, said bus drivers have not changed over the years, but riders have.

“Metro Transit has set a high standard for service that customers have come to expect, and when there is some failure in that — traffic, weather, a breakdown — people get upset” and are more likely to file a complaint, said Lawson, who drove a bus himself for 12 years. “People might be calling in, but that does not make them right.”

Lawson said that driving a bus is a very stressful job, and that he and other drivers have been assaulted, cussed out and even hit with ice balls.

“Our workforce works hard to not get complaints,” Lawson said. “Every driver wants to drive safely, keep customers happy and get them there on time.”

Lawson said nearly every driver at some point gets a complaint. Faye Brown, a bus driver for 20 years, agreed. She said riders are less patient than they used to be.

“I have to be fast and quick with an answer, and if I don’t have it, they think I have an attitude because I’m not helping,” said Brown, who has dealt with complaints by riders. “Really, if I don’t know, I give them the phone number [to Metro Transit] and they think I’m being flip. It’s really more of a misunderstanding and not getting the communication right.”

It’s not only passengers who have gripes. Watts called Metro Transit after a bus driver cut him off on Hwy. 36. Watts said when he later passed bus No. 3337 on June 6, which had passengers on board, the driver gave him the middle finger. Then the bus driver veered off onto the right shoulder, sped up to 50 miles per hour to pass him before cutting back into traffic.

“I was astounded,” he said. “That took me aback.”

The driver was called in for a coaching session, said spokesman John Siqveland. Last year, the agency held 3,377 coaching sessions, in which managers and drivers talk about how to correct the common problems that are reported: drivers who pass up passengers, chronically leave a stop early or depart late, or who aren’t being helpful.

More than 75 percent of vetted complaints are resolved with a phone call to the complainant, said Metro Transit customer relations supervisor Pam Steffan. Often, Steffan says, it comes down to educating the riders: advising them to get to their stop five minutes before the bus is scheduled to arrive, explaining that a route was on detour or a bus stop moved, or guiding them on how to add value to their Go-To Cards.

With bigger issues, such as Jackson’s and Watts’, Steffan said the agency interviews the driver and if necessary pulls a bus’ GPS records or video to “research and validate” a claim and determine whether discipline is necessary.

Drivers can face harsher consequences, such as a non-discipline warning for repeated missteps or a written warning in their file. Thirteen drivers last year got a final written warning, issued after chronic problems over a three-year period. A dozen were terminated.

Drivers with too many complaints also can be referred to the agency’s Transit Ambassador training for a refresher on safe driving and customer service skills.

It’s not always bad news that comes in. The number of drivers getting praise has also risen, from 1,138 in 2008 to 1,462 in 2012. One rider called to say she had the best driver in many months. “The driver called out all of the intersections and the connecting routes. He did an excellent job.”

Others lauded drivers for avoiding crashes, going out of their way to help customers, defusing tense situations and “making the ride enjoyable.” One called her driver “an angel.”

The upward trend in complaints may end in 2013. Siqveland said a cursory look at the data shows a modest drop in the number of complaints filed so far this year. There also are more people taking transit, he said, with ridership up about 1 percent for the first 10 months of the year.