TODAY, British voters are heading to the polls to have their say on EU membership for the first time in a generation.

Attitudes to immigration and sovereignty seem to have been the flashpoints in an increasingly divisive debate, so it is worth setting them aside to consider the EU's role in a different: transport.

So, what has the EU ever done for travellers?

Axing data roaming charges on mobile phones has been one of the key benefits to EU consumers which would be lost if the UK exited.

Charges for texts, calls and data usage were already capped at between one to three pence per minute, or megabyte, on April 30 this year and will eventually be scrapped altogether for EU citizens using their phone in another EU member state from June 2017.

Airline passengers are also entitled to flight delay compensation courtesy of EU Regulation 261/2004. The rule, which came into effect in 2005, entitles passengers to up to €600 per passenger(£460 in compensation) when their flight lands at their destination more than three hours as a result of cancellations, re-routing, delays or overbooked flights.

It applies to any flights taking off from an EU airport or en route to a member-state airport on an EU-based carrier.

Although there have been frequent legal wranglings over what might constitute sufficiently "extraordinary circumstances" to exempt airlines from shelling out, courts have generally sided with consumers - on everything from aircraft technical faults to delays caused by crew or passenger illness.

Flight compensation company, EUclaim, has estimated that Brexit could cost British travellers up to £300 million a year in missed compensation.

Adeline Noorderhaven, UK manager of EUclaim, predicted that UK-based airlines would also lose the pressure to run to schedule if the regulation no longer applied.

She said: "With such steep financial penalties, airlines have had to up their game.

"Since 2011 there has been a 32 per cent decrease in delays. If the UK leaves, this regulation would no longer be binding. There wouldn’t be the same incentive to perform."

There have been downsides, though. Strict EU state aid laws were blamed for killing off Scotland's route development fund, a taxpayer-subsidy scheme which was credited with luring airlines to launch 55 new destinations - including 28 international connections - at Scottish airports between 2002 and 2007. Attention has since switched to APD cuts as an effective replacement for the fund.

Looking to the future, EU transport ambitions largely hinge on its "Roadmap to a single European transport area".

By 2050, the EU wants to phase out conventionally-fuelled cars from European cities, cut road fatalities to almost zero, and reduce greenhouse gas emissions to 80-95 per cent below 1990 levels.

How? Well, one of the strategies is "greater consistency" for transport taxation across member states - potentially outlawing such benefits as tax breaks for company cars - and applying "user charges" to all vehicles to "reflect at least the maintenance cost of infrastructure, congestion, air and noise pollution".

In the end, like much else in the debate, whether you think these ambitions good or bad probably depends whether you prioritise UK sovereignty or more collective action for collective problems.