WALK into a florist in America and take a deep breath: beneath the heady scents of petals and pollen, you might just catch a whiff of jet fuel. Nearly three-quarters of all the flowers sold in the US have travelled through Miami International Airport in Florida. They arrive, typically from Central and South America, alongside planeloads of foreign fruit, vegetables and seafood. In fact, over 70% of the country’s perishable air imports land there. Once the chilled blooms arrive in Miami, they undergo inspection, fumigation, and sorting and are loaded onto lorries for shipment to the city’s warehouse district, 10 miles away. Currently, 35 trucking firms working around the clock rack up over 200,000 trips back and forth each year. Bottlenecks and delays leading to wilting stems can cost this near-$1 billion industry millions, to say nothing of the effects on convalescing companions and lovers left in the lurch.

One problem is that Miami's traffic is some of the worst in America. Tanner Martin, of the Florida Department of Transportation (FDOT) Systems Planning Office, says his journey has averaged 7 miles per hour at times. The FDOT is in the process of building a $60m viaduct across part of the route, which should shave time from the journey. But bigger changes are afoot.

In 2012 Florida became the second US state to welcome autonomous vehicles onto its roads (to date, just four states and the District of Columbia have enacted such legislation). Mr Martin and his colleagues recognise that it is only a matter of time before the state's infrastructure and its legal framework will need to accommodate the vehicles. Currently, though, Mr Martin says the operational impacts and policies to address them are “largely anybody’s guess”.

His vision is of autonomous lorries that whisk bouquets from plane to warehouse in a flash, avoiding pedestrians, cars and other self-driving vehicles while communicating constantly with so-called smart roads (those peppered with sensors, and which can shift traffic-light timing or lane number and direction according to demand). Mr Martin says self-driving lorries could be given extra green time at lights, for example; he reckons even "an extra two seconds here, an extra three seconds there" could have tangible effects on efficiency.

To date, most pilot projects involving automated vehicles have been executed in controlled environments such as test tracks, and data from the few projects that have occurred on public highways are closely guarded. Google recently lobbied officials in California for permission to test self-driving lorries alongside its autonomous cars. What the Florida project needs is just that kind of data—but Google will be guarding its results closely.

The FDOT is now planning a pilot project to gather real-world data for itself, the first such project by a public body in America. Initially, drivers will be given smartphones running apps that collect information on which routes they drive and how long their journeys take at various times and on various days of the year. In the next phase, for which the department aims to secure industry funding, some vehicles will be equipped with "vehicle-to-infrastructure" technology to connect with traffic lights and possibly give them priority during quiet periods. Finally, a few lorries will be retro-fitted with autonomous driving systems that can make the trip to and from the warehouses with little or no input from their human operators, although a driver will always be present.

The first self-driving lorries could be rolling out of Miami's airport in as little as three years’ time. If all goes well, some of Miami’s roads will be smoother and safer, and the state will be more prepared for what now seems an inevitable wave of autonomous vehicles of other sorts. Plus, America’s flowers will be just that little bit fresher; success would rarely smell as sweet.