"All my friends always struggle to get home from parties, I could tell they were starting to make the wrong decisions, so I gave up my Friday and Saturday nights to make sure they all got home from parties on whatever nights they needed to," he said.
"And I've got a couple of other people who started driving for me as well."
It wasn't too much of a leap to go from there to deliveries, the former Orewa College student said.
"Personally, I don't think there are enough taxis up here, but then I thought, why not open it up and start delivering McDonald's to people, because it's probably the only major fast food place that doesn't do deliveries, so it'll be popular."
It was "an extension to the sober driving", he said, "because people get home from parties and they want something to eat, and they don't want to cook".
And despite his initial assumption that he would mostly be catering to people his own age, Mr Broughton said the majority of the interest he's had since posting the comment on Facebook last night has been from adults.
"Last night was the first night I posted about delivering food and all that ... and I did two of them last night," he said, adding they were "both adults".
"All the people that enquired were mainly adults," he said. "Last night I had about 40 people messaging me enquiring about charges."
More than 100 people commented below the post, he said, "saying, 'what an awesome idea', 'you're going to be busy on your Fridays and Saturdays'".
"There was a lot of interest," he said, with a few jobs booked in already.
"I didn't expect that response, I was blown away with it."
However, a number of people warned Mr Broughton that he may need a taxi licence to operate a sober driver pick up service, and that's something he's looking into, he said.
He won't be making any paid sober runs until that's organised, and in the meantime has a number of friends with licenses that can take on that side of the business.
"It was my first night advertising it and prior to that I'd only been driving friends around. But as soon as this kicks off, that will be my first priority [getting the relevant license]," he said.
"I've got two others that can drive passengers and all that sort of stuff.
"For me, I'm just stopping my friends from drink driving."