As technology advances, the terms ‘driverless’ and ‘self-driving’ often blur together, yet they represent distinct levels of vehicle autonomy. What are the definitions, differences, and implications of these two concepts? How do they compare vis-à-vis their merits and demerits, and what is the future landscape of transportation in a world increasingly dominated by autonomous vehicles?

Driverless cars and self-driving cars are terms often used interchangeably to describe vehicles that can operate without human intervention. However, there are some nuanced differences in how these terms are applied.

A driverless car, also known as an autonomous vehicle, is a vehicle capable of sensing its environment and operating without human involvement. These cars use a combination of sensors, cameras, radar, and artificial intelligence (AI) to navigate between destinations. The key characteristic of a driverless car is that it requires no human driver to operate – it can pick up and drop off passengers or cargo without any human intervention.

A self-driving car is a vehicle equipped with technology that allows it to operate with varying degrees of autonomy. While the term is sometimes used synonymously with driverless cars, it often refers to vehicles requiring human oversight or intervention. Self-driving cars can range from those with basic driver assistance features to fully autonomous vehicles.

While the terms are often used interchangeably, there is a subtle distinction. Driverless cars typically refer to fully autonomous vehicles (Level 5 on the autonomy scale) requiring no human intervention. Self-driving cars can encompass a broader range of autonomous capabilities, from driver assistance features to full autonomy. All driverless cars are self-driving, but not all self-driving cars are completely driverless.

To better understand the spectrum of self-driving technology, it’s helpful to refer to the Society of Automotive Engineers (SAE) levels of driving automation.

Most current ‘self-driving’ cars on the market are at Level 2 or 3, while truly ‘driverless’ cars would be at Level 5.

Advantages and disadvantages of self-driving cars

Advantages of self-driving cars which are on Level 2 include:

• Enhanced safety with driver assistance features that can help prevent accidents caused by human error.
• Automated systems that can take over some driving tasks, especially on long journeys reducing driver fatigue.
• Optimised driving patterns leading to better fuel economy.
• Due to incremental adoption, allows for a gradual introduction of autonomous technology, thereby easing public acceptance.

The disadvantages of these cars include:

• An overreliance on technology where the driver may become too dependent on automated systems, leading to reduced alertness.
• Creating confusion over capabilities with misleading marketing using terms like “Autopilot” that can lead to a misunderstanding of the car’s limitations.
• Inconsistent performance where a vehicle may struggle in certain conditions, like poor weather or complex traffic scenarios.
• Have legal ambiguity with an unclear liability in case of accidents involving partially autonomous vehicles.

Advantages and disadvantages of driverless cars

The advantages of driverless cars which are on Level 5:

• Have maximum safety potential that eliminates human error.
• Provide increased mobility by providing transportation options for those unable to drive, such as the elderly or the disabled.
• Improve traffic flow by potentially reducing traffic congestion through optimised routing and platooning.
• Increase productivity where the occupants in the car can engage in other activities while travelling.
• Have environmental benefits as optimised driving and the potential for shared autonomous vehicles could reduce emissions.

The disadvantages of driverless cars include:

• High initial costs as advanced technology makes these vehicles expensive to produce and purchase.
• Could lead to job losses in transportation-related industries.
• Have cybersecurity risks as fully autonomous vehicles could be vulnerable to hacking or cyber-attacks.
• May include ethical dilemmas when programming vehicles to make moral decisions in unavoidable accident scenarios.
• Have sophisticated infrastructure requirements with specialised or high-definition maps to operate effectively.

The Current Situation

As of 2024, truly driverless cars (Level 5) are not yet available for public use. Most advanced consumer vehicles are at Level 2 or 3, requiring driver oversight. However, companies like Waymo and Cruise are testing Level 4 autonomous taxis in limited areas.

Recent data suggests that self-driving cars may already be safer than human drivers in routine circumstances. However, they still face challenges in certain conditions, such as low-light environments and when making turns.

In Singapore, popular autonomous vehicles (AVs) like Tesla and BYD are Level 2. Honda Legend Hybrid EX was the world’s first vehicle to be classified Level 3 in 2021, and Mercedes-Benz’s Intelligent Drive and Drive Pilot followed in 2023 in the S-Class and the EQS.

Our Automonous Vehicle Trials

Singapore started AV trials from 2014:

• October 2014 – SCOT (Shared Computer Operator Transport), by NUS-SMART (National University of Singapore and Singapore-MIT Alliance for Research and Technology), prototypes tested publicly at the Chinese and Japanese Gardens.
• July 2015 – A*Star’s AV was first to be approved for public road testing at one-north.
• September 2015 – NUS-SMART AVs tested on public roads at one-north.
• April 2016 – World’s first driverless taxi from nuTonomy, the first private company spin off from MIT/SMART, approved for public road trial in one-north district.
• Auto Rider, the first fully-operational AV in Asia in collaboration with ST Engineering, used at Gardens by the Bay for visitors.
• NAVIAs, two AVs by Nanyang Technological University (NTU) Energy Research Institute at NTU (ERI@N), Induct Technologies and JTC.
• MooVita’s MooBus in Ngee Ann Polytechnic.

These areas were selected as they are located in a special science and technology district (one-north), campuses, and closed roads. They were also less crowded for safety reasons.

Singapore’s Land Transport Authority (LTA) indicated that AVs will improve traffic safety, and increase productivity by reducing congestion and optimising road usage. In support of this, the LTA, NTU and Jurong Town Corporation set up the Centre of Excellence for Testing and Research of Autonomous Vehicles (CETRAN) in 2017, with a test circuit of 1.8 hectares at CleanTech Park. Since then, over 50 AVs were tested.

Driving into the Future

The future of autonomous vehicles is likely to favour fully driverless cars on Level 5 in the long term, but the path to get there will involve a gradual progression through the levels of autonomy.

Once perfected, driverless cars have the potential to reduce traffic accidents dramatically as they eliminate human error. Fully autonomous vehicles can optimise traffic flow, reduce congestion, and improve fuel efficiency. Driverless cars will provide mobility solutions for those unable to drive, expanding transportation access.

The potential for reduced accidents, lower insurance costs, and new business models like autonomous ride-sharing, could make driverless cars economically attractive. As AI and sensor technologies improve, fully autonomous systems will become more capable and reliable.

However, the transition to a fully driverless future will be gradual. Self-driving features will continue to be introduced incrementally, allowing for public acceptance and regulatory adaptation. Smart city infrastructure and high-definition mapping will need to evolve to support fully autonomous vehicles.

Regulations and ethical guidelines for autonomous vehicles will need to be developed and refined. Achieving Level 5 autonomy in all possible driving conditions remains a significant technical challenge. Building public confidence in fully autonomous vehicles will take time and require demonstrated safety records.

In the near to medium term, it’s likely to see a mix of human-driven vehicles and cars with various levels of autonomous capabilities. Level 4 autonomous vehicles may become more common in controlled environments or on specific routes like the highway before Level 5 vehicles are widely available.

The development of self-driving technology is not just about replacing human drivers but about reimagining transportation. As one progresses towards fully driverless cars, it’s likely to see new vehicle designs, changes in urban planning, and shifts in how one thinks about car ownership and use.

While self-driving and driverless cars are often discussed interchangeably, they represent different points on the spectrum of autonomous vehicle technology. Self-driving cars, with varying levels of autonomy, are already on the roads, offering enhanced safety features and driver assistance. Fully driverless cars, while still in development, promise a future of increased safety, efficiency, and accessibility.

The Road is Still Long

The journey towards widespread adoption of driverless cars will be gradual, marked by incremental improvements in self-driving technology. This evolution will be shaped by technological advancements, regulatory frameworks, infrastructure development, and public acceptance. Moving forward, it’s crucial to maintain realistic expectations about the capabilities of current self-driving technologies while working towards the goal of fully autonomous vehicles. The future of transportation is likely to be driverless, but the road to get there will be paved with many iterations of increasingly sophisticated self-driving technologies.