Informal and illegal cross-border taxis have been around for more than a decade but have proliferated in recent years, aided by technology and the spread of social media platforms. After agreeing on a fee which can range from $10 to $30 per person, passengers are ushered into a car, usually a Multi-Purpose Vehicle (MPV), joining others to make the trip across the Causeway, reported The Straits Times. 

A recent Straits Times report found at least 20 making use of apps like Facebook or WeChat to advertise and organise services. Mostly Malaysia-registered vehicles, some even provide on-call, door-to-door rides that pick up groups of 10 to 12 in Singapore and take them to tourist attractions in Johor like Legoland Malaysia.

Their growth has made licensed cross-border taxi drivers cry foul, even with rules being relaxed in 2012 to allow them to pick up and drop off passengers anywhere in their own countries.

Currently, there are 173 and 187 taxis from Singapore and Malaysia respectively that are licensed to ferry passengers across the border, according to the Land Transport Authority (LTA), with a total of 400 permits available. They charge fixed fares, with a trip from the Ban San Street terminal to JB's Larkin bus terminal costing $48 per taxi, or RM80 ($27) in the opposite direction.

The LTA said it issued warnings to four offenders for operating illegal taxi services from Ban San Street terminal in 2014, and prosecuted four last year for the same offence. Any person caught using a foreign-registered motor vehicle as an unlicensed public service vehicle to convey passengers for hire and reward can be fined up to $3,000 and jailed up to six months. Vehicles used in the commission of such offences may also be forfeited.