Interested in this kind of news? Receive them directly in your inbox. Delivered once a week. Sign Up This sounds revolutionary but it has been done before; the problem is the road transport sector is just lagging behind. In fact, all Google and the like are talking about is revolutionising mobility in the same way they’ve transformed information, communication, shopping or the hotel business. It’s really not that different for cars. There are a whole lot of them – 239 million in the EU – but they have always been underused. Around 90% of the time cars are parked and when they’re driving they’re often stuck in traffic, with on average 1.6 persons in it. If that sounds inefficient, that’s because it is. Thus, sharing cars makes perfect (economic) sense. Enter the digital revolution: BlaBlaCar and Zipcar have already convinced millions of people to share (their personal) vehicles and now Uber and others are developing carpooling apps that have the potential to completely upset city mobility. Autonomous and electric vehicles would only accelerate this trend. It all sounds radical but in essence it’s just a matter of leveraging what Robin Chase from Zipcar called the ‘most underused asset in the world’. For us greenies, 90% fewer cars would surely be an enticing proposition. There would be space for parks, cycling lanes, new housing or playgrounds. We could truly give cities back to citizens. But we need to be on our guard. Indeed, hidden in the ITF estimate is the fact that only much cleaner cars would make this mobility revolution a good thing for the climate. Yes, the spectacular increase in transport efficiency would cut the number of cars. But it would surely increase personal mobility (passenger kilometres), and its impact on overall traffic (vehicle kilometres) is still unclear and depends on the way the transition is managed. There are some key lessons for policymakers here. As Robin Chase said: ‘Governments need to adapt or they will fail.’ For example, unless governments overhaul their post-war taxation regimes, the mobility revolution could bankrupt them. Revenue from car registration and fuel taxes would collapse. One obvious and smart way to shift taxation would be to introduce a km-based toll for all vehicles to replace lost revenue, manage traffic and prevent big rebound effects. EU transport Commissioner Bulc understands this and wants to propose a European car tolling framework that member states could opt into. Another key lesson is that we still need cleaner vehicles. The EU is gearing up for 2025 CO2 limits for new cars and vans. If sufficiently ambitious, these could help put us on course to decarbonise cars by the middle of this century and hand Europe back the leading edge in the global race for cleaner cars. The on-going digital revolution is making things easier. Car sharing drastically improves the attractiveness of fuel-efficient vehicles that are typically expensive to buy but cheap to run. The world is changing rapidly. This creates huge opportunities, not just for entrepreneurs and big business but also for the green movement. We should embrace disruptive change and use it as a force for good. And we should make sure governments don’t waste the opportunity. Ambitious standards and green tax reform will be the litmus test of governments’ resolve.