Figure 2: Aspects of Autonomous shuttles and concerns
The poised technology and regulatory stance
Autonomous shuttles are the sweet spot for self-driving technology deployment with minimal chances of on-road fatalities and continuous technology improvement. The vehicle size is perfect, making it fall under the LSV category, with potential for regulatory relaxation as detailed in the case below.
Nuro R2X is Nuro’s second-generation unmanned and occupant-less delivery vehicle. In February 2020, Nuro managed to get certain exemptions from the NHTSA & FMVSS for the R2X vehicle, on the premise that the vehicle is occupant-less3. Firstly, removal of exterior and interior rear-view mirrors; secondly, doing away with real-time display requirements for the rear-view camera; lastly, on the usage of glazed material windshield that was meant to protect occupants. This, in turn, makes R2X safer for pedestrians. R2X also boasts a crumple zone in the front-end design, thereby reducing the impact on a road user.4
Safety standards and testing protocols for automated functions aren’t matured in the shuttles space. Since autonomous shuttles do not have pedals, steering wheels, they do not comply with NHTSA guidelines.5
Mapping for Autonomous shuttles
Autonomous shuttles move on pre-mapped routes. The route that these vehicles are supposed to follow are stored locally in the shuttle and accessed to make the vehicle move predictably, stopping only at boarding or de-boarding stations or for emergency stops.
The operational specifics of the shuttle are also decided based on this route. Any autonomous shuttle needs to precisely locate itself on this pre-defined map. This is known as localization and is achieved by prior knowledge of landmarks and real-time sensor observations made by the vehicle. As part of the deployment checklist, if the experts from the autonomous shuttle company so deem, new features are “installed” on the route chosen to ease localization.
The operations team has to ensure safety of the occupants as well as road users who are a part of the dynamic environment. Events like diversions owing to accidents or temporary construction zones etc. will have to be controlled by the remote operations team. Any detour requires surrounding road network knowledge and that may not always be the case. Per Optimus Ride’s CEO, a “geo-fenced strategy” is being used for Autonomous shuttles.6
Detailed mapping data of the intended route is saved locally in onboard storage. This helps with unanticipated events that trigger the safe-stop mode of the shuttle.7
Restricted Operational Design Domain
Deployments of Autonomous shuttles so far have happened in constrained and more protected environments. As depicted in figure 1, these environments include university campuses, hospital premises, closed corporate parks, technology parks, and some pre-determined routes for carrying people with known boarding and de-boarding areas. Within these enclosed spaces, too, is a spectrum of complexity. An airport deployment use-case for movement of people from security to boarding gates is a less complex ODD as compared to in-city driving for delivery of goods, which is almost on the other extreme of the spectrum.
Every critical system in autonomous shuttles like acceleration, braking, sensors, computing, and steering systems have built-in layers of redundancy; in most cases, they have triple redundancy. Autonomous shuttles are at level 3/4 of autonomy per SAE (depending on the application). Level 4 autonomous vehicles are constituted by ISO26262 described ASIL C or ASIL D components at the hardware & software level.
The vehicle is designed to come to a safe stop when it exits its intended ODD. For example, if an autonomous shuttle is designed for wet roads, but not for icy or snow-covered roads, then the remote operator can intervene if such a scenario arises.
The onboard computer in these shuttles is programmed to compute the trajectory to be taken for a safe stop, keeping in mind various dynamic environment factors like traffic/obstacles in the immediate vicinity.
Along with Product Safety, Deployment safety and Operational safety are two major focus areas where autonomous shuttle companies ensure safety standards are adhered to.8 As part of deployment safety, an onsite team inspects the route and gets it ready for shuttle deployment. The operations team may also have an onsite pre-trip checklist, an Operations Manager along with a team who is contacted in case the shuttle comes to a safe stop.
Staying relevant in the COVID era
COVID-19 has had people stay put where they are. There has been a shift from people movement to goods movement. This shift is seen on the employment side, with people employed in taxi or cab services moving to goods delivery. The shift also means implications for autonomous shuttle companies, and they are repurposing shuttles meant for movement of people into goods carriers. There is a last-mile delivery boom, with Uber Eats search increasing by 70%, DoorDash 55%, Grubhub 46%, and Postmates 42%9. With this boom, Optimus Ride, Beep, Gatik, and Cruise are now delivering food10.
This section talks about the infrastructure capabilities required for Autonomous shuttles and some aspects that require improvement.
Are autonomous shuttles to stay with us for long? The accelerated deployment of autonomous shuttles is winning the autonomous machines’ ecosystem the necessary opportunity for eventual technology perfection, so autonomous shuttles apparently are the intermediate step in autonomous technology real-world deployments. If this is the case, are we creating “room” for them to “thrive” alongside passenger vehicles?
For reasons similar to why trucks are a threat to passenger vehicles on highways, passenger vehicles will be threats to these shuttles. The weight of trucks could be as much as 20-30 times the weight of other passenger vehicles.11 The weight of passenger vehicles is typically between 2,000 to 5,000 pounds, but could be greater for light trucks and vans (LTVs)12. The weight of passenger vehicles is hence more than twice that of LSVs. This puts autonomous shuttles at greater risk during collision and consequent fatalities with any other motor vehicle on the road.13
A good approach? Creating extra room for autonomous shuttles, at least wherever there is scope. Wherever smart cities or smart campuses are being made, dedicated lanes could give them multiple advantages (refer figure 3). Currently, one other constraint in their deployment is that they can share driving space only with slow-moving traffic. With a dedicated lane, the possibility is that since all autonomous shuttles moving at a low speed will use a dedicated lane, they will be safer.