As the previous examples show, not making a choice is itself a choice with potentially fatal consequences. Even if inevitable collisions are rare, programmers will still need to apportion the risk of accident between different parties, decide how aggressively cars should drive, and determine when the vehicle should brake or swerve.

Currently, many of these decisions are made by autonomous vehicle manufacturers. In Canada, autonomous vehicle approvals are the joint responsibility of federal and provincial governments. Provincial governments are in charge of licensing vehicles, approving tests and guaranteeing the safe operation of vehicles.

Provincial governments have not demanded to see the source code underpinning vehicles' driving software prior to allowing participation in self-driving pilot programs.

According to Transport Canada, autonomous vehicle trials have only occurred in Ontario, Quebec, Alberta and British Columbia.

In 2016, Ontario launched a 10-year pilot program allowing the public testing of autonomous vehicles. Participants include companies and academic institutions such as Uber and the University of Waterloo. Recently announced changes to the program will allow cars with no driver behind the wheel to drive on public roads.

Ontario's Ministry of Transportation declined to make a representative available to answer questions by phone or in person. In an email, a representative said the goal of the program is to "optimize the transportation system, promote economic growth and innovation, and align with other jurisdictions where possible, while protecting road safety."

In Quebec, Keolis Canada operates a 15-passenger electric shuttle bus provided by French company Navya on a two-kilometre stretch of public road in the city of Candiac. Stéphane Martinez, director of safety policy at Transport Quebec, admits there's a risk with anything that moves but says that risk is a calculated one. According to Martinez, the risk-control measures for autonomous shuttles are significantly higher than for other vehicles on the road. "We don't take Quebec's population as hostages or as guinea pigs."

How autonomous? Vehicles are classified on a scale ranging from zero to five, in order of increasing autonomy. The scale was proposed by engineering standards body SAE International and has been adopted across the industry. Simplified | Detailed Levels 0–2 Human is driving, but may be assisted by sensors or support features like adaptive cruise control and lane centering. Levels 0–2 Human is driving, but may be assisted by sensors or support features like adaptive cruise control and lane centering. Levels 0–2 Human is driving, but may be assisted by sensors or support features like adaptive cruise control and lane centering. Levels 0–2 Human is driving, but may be assisted by sensors or support features like adaptive cruise control and lane centering. Level 3 Automated systems can drive the car in some conditions, but human driver must remain vigilant and take over driving when necessary. Levels 4–5 Automated systems drive the car. Pedals and steering wheel may be absent. Fully autonomous cars do not yet exist. Levels 4–5 Automated systems drive the car. Pedals and steering wheel may be absent. Fully autonomous cars do not yet exist. Level 0 Human is driving, but support features provide warnings, such as lane departure alert, and momentary assistance. Level 1 Human is driving, but support features can control steering, or control braking and acceleration, but not both simultaneously. Level 2 Human is driving, but support features can control steering, and simultaneously control braking and acceleration. Level 3 Automated systems can drive the car in some conditions, but human driver must remain vigilant and take over driving when necessary. Level 4 Automated systems drive the car under limited conditions. Pedals and steering wheel may be absent. Level 5 Automated systems drive the car under all conditions. Fully autonomous cars do not yet exist. Source: SAE International

Ontario and Quebec have recently approved the public use of cars where computer systems can control the vehicle, as long as a vigilant driver is present to take control when needed. These are classified as having Level 3 autonomy, according to a scale produced by engineering standards body SAE International (formerly Society of Automotive Engineers). Level 3 vehicles are not yet available for sale in Canada.

However, an eye-tracking study published by the Institute for Transport Studies of the University of Leeds in the United Kingdom shows drivers require as long as 40 seconds to fully regain "adequate and stable control of driving from automation." In addition, a safety report published by Waymo, a subsidiary of Google's parent company and an industry leader in autonomous cars, said that human drivers "were not monitoring the roadway carefully enough to be able to safely take control when needed." The company is focusing on fully autonomous vehicles (SAE levels 4 and 5) to avoid what it calls the "handoff problem."

In March 2018, a vehicle belonging to American ride-sharing company Uber killed pedestrian Elaine Herzberg, 49, as she crossed a road in Tempe, Ariz. An initial National Transportation Safety Board report indicated the vehicle was configured to require driver intervention for emergency braking. However, the driver failed to take control from automated systems in time to avoid the accident. Uber spokesperson Sarah Abboud confirmed that in the aftermath of the crash the company overhauled its operating practices to be less reliant on the driver. Uber, which participates in Ontario's self-driving car pilot program, suspended road testing in North America as a result of the crash but has since resumed limited testing.

Electric-car manufacturer Tesla's Autopilot system has also been involved in multiple fatal car crashes worldwide.

With interest in autonomous vehicles rising as the technology advances, Canadian governments are faced with their own moral dilemma: How much risk is tolerable today to potentially save lives in the future?