Denise Roney has gone without a car since June 9, when, she says, an MBTA supervisor in a T-owned SUV tried to make a left turn against traffic and plowed into her car.

The crash instantly ruined Roney’s day.

What Roney didn’t realize is that this minor accident would practically ruin her whole summer as well. She has spent months trying to get the T to pay for repairs.

Roney doesn’t have an extra $5,000 laying around — nor does she have collision coverage on her 7-year-old Ford Escape — so the battered car has been in front of her house in Lynn, too damaged to drive, too expensive to repair.

At first, Roney figured the MBTA would quickly pay up. When private parties are involved in an accident, drivers can usually expect to be back on the road within a couple of weeks, no matter who was at fault, according to insurance agents I talked to.

But Roney had opted out of collision coverage, to reduce her premium. Collision insurance pays to repair or replace your damaged motor vehicle, no matter who’s at fault. Most drivers have it and pay dearly for it. If you have it, your insurer will cover the cost of repairing your car (minus any deductible, of course). If you weren’t at fault, your insurer then goes after the other driver’s insurer for reimbursement.

Collision insurance costs hundreds, if not thousands, in annual premiums, the most expensive item in most people’s policy. If your car is financed — or leased — it’s mandatory.

Roney acted a little embarrassed when I asked why she didn’t have collision insurance. Two years ago, she was cited for having an expired inspection sticker. That triggered a $300 surcharge on her insurance for three years. Roney decided to “pay’’ for it by dropping collision. It seemed like a good idea at the time. Not so much now.

Still, she figured she wasn’t at fault for the crash and shouldn’t have to bear the cost. I think she’s right. And I think she would have gotten a quicker resolution if the other driver had private auto insurance.

Instead, she had to deal with the MBTA, a public authority not known for stellar customer service. Who can forget the T’s total shutdown in the stormy winter of 2015? It has a well-earned reputation as a political patronage haven.

The MBTA and other big government entities don’t buy insurance the way the rest of us do. They self-insure, which means they set aside money in their budgets to pay claims when they are at fault.

The T has more than two dozen lawyers and other staffers in the legal office that handles, among other things, such claims as Roney’s. The T’s annual revenues top $1 billion.

You would think the T would know how to process claims promptly.

But Roney couldn’t get the T to return a phone call. For weeks, then months.

In desperation, Roney took the advice of a friend and e-mailed me.

“I’ve been able to borrow other people’s cars to get to work,’’ she wrote. “But it has been such a hassle and very stressful. I’m not sure how much longer I’ll be able to do that.’’

I sent a detailed e-mail to the T on Aug. 21, attaching copies of the claim Roney filed with the T in June; the police report on the crash; the claims adjuster’s report; and the T’s form letter to Roney (“Dear Sir or Madam’’).

“Without the T paying the claim, she’s without transportation for two months,’’ I wrote. “What’s the story here?’’ Nothing.

I sent another e-mail the next day. Someone in the communications office responded within an hour with an apology for the delayed reply, adding that Roney’s case “is being investigated.’’

I asked for a phone conversation and instead got a reference to “Section 4 of Chapter 258,’’ a state law that sets out the process for filing a lawsuit against the T and other public agencies.

Roney wasn’t suing the T. She had simply done what the T told her to do in the form letter.

The T’s e-mail to me also said the MBTA was empowered to settle any claim by paying for repairs after an investigation.

So I asked for the status of the investigation. The T certainly had not reached out to Roney to interview her.

I followed up with a bit of legalese of my own, sending along “211 CMR 74.04(15),’’ the state Division of Insurance regulation that makes the driver of a motor vehicle turning left into traffic presumptively at fault in a crash. The police report shows that’s what the T driver did.

When I arrived at Roney’s Lynn home the next day for an interview, she was smiling broadly. “Guess who just called me?’’ she asked as I climbed the front steps.

The first call had come at 9:39 a.m. from Antonio Perez, a T claims administrator with whom Roney had left voice messages most recently on July 24 (10:44 a.m. and 2:14 p.m.) and July 25 (9:34 a.m.). He said he wanted to help.

Roney, awaiting my arrival, did not immediately return the call. But 36 minutes later came a second, even more fulsome call.

“If you have any questions I would be happy to speak with you,’’ Perez said in the recorded message, which Roney played for me.

“That’s a sudden shift,’’ Roney said.

After the interview, Roney and I jumped into my car and took a ride to Wyoma Square, where the crash occurred. The driver of the T vehicle, Sean Mills, told police Roney’s car hit his. But the crash occurred when Mills turned into Roney’s lane. Drivers turning left at that location are supposed to wait in a protected lane for traffic on the other side to clear.

“Mills took a left-hand turn right in front of me as if he didn’t even see me,’’ Roney wrote in her claim. Mills could not be reached for comment.

While we were busy checking out the crash site, Roney missed a third call from the T, at 11:47 a.m. These folks at the T were suddenly extraordinarily motivated to reach her.

Roney returned the call. Perez seemed only too willing to accommodate her, though he offered no apology or explanation for the delay. And, no, it wasn’t pure coincidence he was calling now, he said.

“Someone’’ at the T “had mentioned something about the Globe’’ asking questions about Roney’s claim, he said.

To date, the T has made no offer and Roney’s smashed car remains in front of her house.

Lessons learned? Think carefully before dumping collision insurance and stay away from wayward T vehicles at all costs.

Sean P. Murphy can be reached at smurphy@globe.com. Follow him on Twitter @spmurphyboston.