A core appeal of driverless vehicles is the congestion savings that they promise to bring to our towns and cities. While there remains some doubt about whether these savings are realistic, a new study from Florida Atlantic University suggests that the biggest savings may not even require autonomous vehicles at all.
Rather, the authors believe that pooled-ride services, such as public transport and car pooling are more likely to deliver the reductions in congestion that we so crave.
The concept rests on the simple premise that the best savings will come when we put more people into each vehicle on the road. The results come after simulations into the way various modes of transport influence congestion in a city.
“Pooled-ride services will help to address some of the transportation system’s most intractable issues and offer affordable flexibility to those who do not own a vehicle or cannot drive, while reducing congestion at the same time,” the researchers say. “The key to successful pooled-ride services is to manage a large number of travel requests centrally, which results in fewer vehicles as well as reduced vehicle miles, travel costs, environmental impacts and congestion.”
Pooling resources
The simulations suggest that the potential for two-passenger ride pooling is almost 100% of trips in the majority of cities so long as trip demand is at least 6.5 trips per hour per square kilometer.
“Sharing rides reduces travel costs for obvious reasons like splitting the cost across two or more parties,” the researchers say. “But it goes beyond just those cost savings. When a passenger agrees to a pooled ride, it allows the transportation service provider to economize by using a smaller fleet, substantially reducing capital costs.”
What’s more, such ride pooling services may also have a positive impact on the environment. The researchers suggest that buses are typically 41% more fuel efficient than private vehicles, due in large part to the low occupancy rate of the cars. By having two passengers per vehicle, rather than the 1.15 that is common, this raises the fuel efficiency by 66.5%, which renders a car pool more efficient than a bus.
While this is based upon almost 100% ride sharing, the data makes clear that even modest levels of ride-pooling can yield significant environmental and congestion benefits, especially during peak times when traffic is at its worst.
What’s more, implementing ride pooling doesn’t require anywhere near as much technology as autonomous vehicles, with the only real technical challenge to ensure the vehicles are coordinated in real-time, which is largely a technology that already exists. If these systems can be implemented alongside public transport systems then it can ensure the most efficient modes of transport are always chosen. This shouldn’t be taken to suggest rolling out such a network will be straightforward however, as it will be anything but.
“The idea of ride-sharing is a complex social issue involving concerns such as safety, privacy and convenience,” the authors explain. “The willingness of people to pool rides depends upon establishing norms of behavior and developing systems that enable people to feel safe and comfortable.”
The researchers plan to conduct further research into the hurdles to overcome in creating such a car pooling network, not least in terms of the safety concerns people may have when sharing rides with strangers. Given the benefits they’ve identified, it’s research that will make fascinating reading.
