MADRID (AP) — Hundreds of drivers are blocking a central artery in the Spanish capital to protest the government’s plan to approve new rules limiting the operations of app-based ride-hailing services

The drivers, who work for companies including Uber and Cabify, brought traffic in Madrid’s Paseo de la Castellana to a standstill as they moved slowly toward the gates of the Development Ministry.

They plan to repeat their protest on Friday, when the government is expected to pass a decree giving local governments the power to limit licenses for the ride-hailing services.

On Wednesday, the companies offered free rides in several Spanish cities. The move furthered angered taxi driver unions, which have been demanding a ratio of 1 ride-hailing car to 30 public taxis.