While their aerial counterparts are still primarily in the conceptual phase, the technology to not only build, market and sell but put driverless cars on our streets is already here. In fact, the Boston Consulting Group estimates that, by 2030, nearly a quarter of “all miles driven” in the US will be from shared self-driving cars. ABI Research estimates that, also by 2030, there will be 11 million shared driverless vehicles on the road globally – or about 5 percent of the world’s traffic population. The reality is, although questions of legislation, liability and ethics remain, nearly all major automotive companies have autonomous vehicles in the works, being tested and/or on the road. We’re nearing a time when driverless vehicles might very well become the majority. It’s important for municipalities to consider just how much this innovation could impact how (and where) we design our roadways, intersections and pedestrian crossings. Below we look at the changes driverless technology will bring, the impact on roadway design in both urban and rural settings, whether autonomous vehicles will help or hinder traffic and steps you can take today in preparation for the innovative horizon. Roadways of the present: built for human drivers, pedestrians To understand how today’s roadways will change with the advent of driverless vehicles, it’s important to first understand the makeup of today’s roadways and intersections. Pictured below is a common intersection style found outside many metro areas: a four-lane with a six-lane divided urban highway.

The roadway and intersection are designed to move human-led cars and trucks. Timed signals guide cars safely along the corridor, which is designed to accommodate peak congestion hours. There are separate, dedicated turn lanes – each with their own markings – making a total of nine lanes, and measuring approximately 140 feet in width. As a result, and in order to accommodate pedestrians, refuge spots exist in the middle of each road for pedestrians who cannot make it completely across in one signal phase. The land surrounding the road is used largely for parking lots, which accommodate drivers visiting area stores and restaurants. Near the bottom of the illustration, there is a frontage road that provides local access. This efficient and effective design makes sense for the early 21st century. But what about a future where “smart” vehicles are the majority? Receive great insight like this monthly

Subscribe How driverless vehicles will affect roadway design Interesting things happen to a road when we incorporate the anticipated capabilities of driverless cars into a redesign. The most obvious difference is a significantly reduced footprint and narrower right-of-way.

Designing for driverless cars could mean much narrower roads with fewer signs, less pavement and, potentially, less maintenance. Click to open full-size version in another tab.

At first glance, a narrower road may seem illogical as the same, if not higher, traffic volume would demand a wide roadway. But here’s why this might not be true: if driverless cars have the predicted effectiveness over current drivers, the same traffic volumes could flow through a narrower roadway designed with narrower lanes and fewer of them. In fact, lanes likely wouldn’t need to be much wider than a delivery truck. In addition, when we can confidently rely on vehicle sensors and interconnectivity, there will be no need for the visual cues (e.g., road striping and signage) that human drivers rely on. As also illustrated in the image above, the pedestrian crossings are moved away from the intersection. Today, for safety reasons, most pedestrian facilities exist at controlled intersections. Although this makes sense, it also requires pedestrians to walk extra blocks in order to legally cross a roadway. Since signalization is not necessary with driverless cars, crosswalks could be placed at the optimal place for pedestrians. With algorithms, GPS and complex computers replacing road signs, traffic signals and smart phones (for GPS purposes), an unprecedented intermodal efficiency becomes possible. An efficiency that could significantly impact not only how we move, but also how and where we live.

Goodbye, parking lots? Driverless cars could change not only how we move, but how we live. Click to open full-size version in another tab.