Taxi-booking app goCatch will begin paying drivers to pick up early-morning passengers at notorious Sydney trouble spots.

In a month-long trial starting on Friday, drivers will be paid up to $20 a trip to take fares between 1am and 4am from central Sydney and Kings Cross.

GoCatch will report the results to the NSW government, which on Tuesday announced measures to crack down on drug- and alcohol-induced late-night violence in those areas.

App co-founder Andrew Campbell says many drivers avoid areas with a reputation for violence.

"They tell us that it's not worth the hassle and aggravation," he said.

"Sometimes demand outstrips supply and passengers have difficulty finding a cab.

"We have to find a way to encourage the drivers to return to the city, and hopefully this measure is one small way to do that."

He hopes a successful trial will lead to a partnership with the government to introduce the incentives across NSW.

GoCatch is a free app for Android and iOS that allows users to book a taxi directly with a driver and to see the location of taxis on their phones.