A key benefit of automated transit is its ability to reduce auto Vehicle Miles Traveled (VMT) and parking requirements. Many of these same benefits can be achieved by using robots operating on sidewalks to deliver small items, thus eliminating person trips to and from stores and restaurants by any mode. In the case of items that are already being ordered online and delivered, sidewalk robots can reduce local truck traffic. In some cases, automated transit and sidewalk delivery robots will serve the same geographical area, and a comprehensive planning model will benefit from taking both into account.
With the exception of the Rivium ParkShuttle, which allows pedestrians and autos to cross its dedicated roadway at grade in certain locations, automated transit systems currently require human on-board supervision or an exclusive guideway. Delivery robots, on the other hand, are now making hundreds of deliveries every day on public sidewalks with no human supervisor nearby.
In addition to small sidewalk robots that travel 4-6 mph (6-10 kph), larger robot delivery vehicles that operate on roadways are also being developed. While these show promise, they are currently not autonomous and require either an on-board supervisor or a chase car when operated on public roads. Only sidewalk robots will be considered below.
CURRENT STATE OF SIDEWALK ROBOT INDUSTRY
A number of companies are now developing sidewalk robots, and big names include Amazon, FedEx, and PostMates. The current leader in the field in terms of actual systems deployed is a smaller company named Starship Technologies (www.starship.xyz ) which is currently operating hundreds of robots in the US and UK with no accompanying human attendants.
Over 30 Starship robots are operating at the Fairfax, VA campus of George Mason University (GMU) just outside of Washington, DC. The robots can be remotely controlled by human operators when necessary but are mostly autonomous. In addition to operating on sidewalks, they can cross streets at marked crosswalks. Similar fleets of Starship robots are operating at Northern Arizona University, Purdue University in Indiana, and in the town of Milton Keynes in the UK.
The Starship robots use cameras and ultrasonic sensors to determine their immediate environment, and radar to assist the cameras in detecting oncoming cars when crossing a street. Robots from some competing companies also use lidar. While Starship robots have GPS, their primary method of localization is to match prominent straight lines currently visible with corresponding lines in photos taken earlier of the same area. This gives the robot’s location to within 2 inches (5 cm).
The Starship robot and most of its competitors operate only outdoors. This simplifies operations since the robots don’t have to go through doorways, nor are there concerns about losing GPS signals and communications links while indoors.
In the US, where Starship robots operate mostly on university campuses, the deliveries are generally snacks or fully prepared meals. In Milton Keynes, deliveries are to individual residences and also include groceries and small packages. The delivery surcharge is currently $2 in the US and one British Pound in the UK. In a typical US campus system, a restaurant or convenience store employee places the delivery into one of the robots waiting just outside their establishment. The robot then travels to a location on campus specified by the consumer at the time the order was placed, and he or she is notified by text message to meet the robot. The consumer then uses their phone to unlock the robot’s lid so they can access the delivered items.
The primary requirement for a system of sidewalk delivery robots is, of course, a suitable network of sidewalks that are wide enough to allow robots to easily pass oncoming pedestrians. Since the Starship robot is about 22.4 inches (57 cm) wide, this implies a minimum sidewalk width of about five feet. Competing robots have similar widths. The robots at GMU generally travel on sidewalks at least eight feet (245 cm) wide.
The CBDs of many older cities have narrow, congested sidewalks that put robots at a disadvantage compared with alternative delivery modes, such as bicycle couriers. In newer Major Activity Centers and in many suburbs the sidewalks have adequate width and are less congested, thus facilitating robot operation.
In addition to a suitable network of sidewalks, a practical robot delivery system needs a high enough density of potential customers to make it economically viable. Too low a density would require excessive trip lengths which would reduce the number of customers per day each robot could serve. This is why most of the systems deployed so far have been on large university campuses where tens of thousands of students, faculty, and staff can be served by robots with a typical trip length of less than 0.75 mile (1.2 km).
Many of the same moderately dense urban areas that look promising for automated, at-grade shuttles such as the EasyMile EZ10 and Local Motors Olli, also work well for sidewalk delivery robots. Unlike shuttles which still operate in test mode with attendants, delivery robots are now fully operational in multiple locations. By the time automated shuttles are deployed in significant numbers, it can be expected that sidewalk robots will be commonplace. Since delivery by robot is sometimes an alternative to a person trip on a shuttle, transportation models will ideally take both modes into account.