Hundreds of taxi drivers have been driving slowly on Budapest's main thoroughfares to protest ride-hailing apps like Uber and what they say is a growing market for unlicensed passenger transport.

Taxi drivers have also parked in a long line on one side of the Chain Bridgndnde across the Danube River, further complicating downtown traffic.

Drivers say they have invested heavily to comply with regulations which, for example, compel Budapest taxi cabs to be painted yellow.

Geza Gottlieb, an organizer of Tuesday's protest, says over 50 percent of the taxi trade is part of the black economy, "carrying passengers illegally and without permits."

Gottlieb said that while authorities had carried out some "show procedures," including removing license plates off unlicensed taxis, nothing had really changed since similar protests earlier this year.