How Do Self-Driving Cars Work? – AI, Sensors, and Decision-Making

Self-driving cars are no longer just a sci-fi fantasy — they are becoming real-life players on public roads. Autonomous vehicles represent a breakthrough enabled by advances in artificial intelligence, sensor technology, and data analysis.

But how can a car drive without a human behind the wheel? What tools does it use to perceive its environment? What algorithms guide its decisions? And when will we see fully autonomous vehicles on Hungarian roads?

This article provides a detailed yet accessible explanation of how self-driving technology works, from sensors to AI to on-the-road decisions.

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Table of Contents

1. What Counts as a Self-Driving Car?

2. The 6 Levels of Autonomous Driving

3. The Vehicle’s “Eyes” – Sensors and Their Roles

4. The Vehicle’s “Brain” – How AI Processes Data

5. How Decisions Are Made: What Happens When a Pedestrian Appears?

6. Current Solutions – Tesla, Waymo, Mercedes-Benz

7. Risks and Current Limitations

8. When Will Robot Cars Rule the Roads?

9. The Hungarian Landscape: Research and Regulation

10. Conclusion

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1. What Counts as a Self-Driving Car?

A self-driving vehicle is an autonomous system capable of perceiving its environment, making decisions, and controlling itself without human intervention.

It’s important to differentiate driver-assist features (like lane keeping or adaptive cruise control) from true autonomy. Real self-driving means no human input is required at any point.

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2. The 6 Levels of Autonomous Driving

According to the SAE (Society of Automotive Engineers), autonomous driving is categorized into 6 levels:

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3. The Vehicle’s “Eyes” – Sensors and Their Roles

Self-driving cars use a variety of sensors to build a detailed picture of their surroundings:

Camera

• Detects lanes, signs, pedestrians.

• Wide field of view but limited in low-light conditions.

Radar

• Uses radio waves and performs well in bad weather.

• Primarily used for distance measurement and vehicle tracking.

Lidar (Laser Scanning)

• Creates a 3D map of the environment.

• Highly accurate but expensive and sensitive to debris.

Ultrasonic Sensors

• Useful for short-range detection, e.g., parking assistance.

All sensor data is fused and interpreted in real time by the vehicle’s AI.

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4. The Vehicle’s “Brain” – How AI Processes Data

The central computer in the vehicle is the “robot driver”. It runs machine learning algorithms that:

• Process sensor data,

• Detect objects (cars, humans, traffic lights),

• Analyze their movement,

• Predict what happens next,

• Make driving decisions.

Example: If the AI sees a pedestrian approach a crosswalk, it anticipates crossing and slows down automatically.

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5. How Decisions Are Made

Real-time decision-making follows three major steps:

1. Perception – sensing the environment.

2. Interpretation – object recognition and behavior prediction.

3. Action – choosing and executing the maneuver (braking, turning, accelerating).

AI makes decisions based on thousands of past scenarios, often faster and more consistently than a human driver.

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6. Current Technological Solutions

Tesla Autopilot / Full Self-Driving (FSD)

• Camera-based system.

• Currently Level 2, under continuous development.

Waymo

• Owned by Google, Level 4 robotaxi.

• Uses lidar, radar, and cameras together.

Mercedes-Benz Drive Pilot

• Level 3, approved in Germany.

• Operates autonomously on highways at limited speeds.

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7. Risks and Limitations

• Ethical dilemmas: Who should the car “choose” in an unavoidable crash?

• Technical limitations: Snow, fog, missing road markings.

• Legal barriers: Higher levels not legally permitted in most countries.

• Cybersecurity threats: Data protection and hacking risks.

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8. When Will Robot Cars Rule the Roads?

Experts predict:

• 2025–2027: Level 3 and 4 systems will be common in controlled environments (e.g., robotaxis in urban zones).

• Post-2030: Level 4–5 fully autonomous driving may roll out in select countries.

In Hungary, full autonomy may take longer due to infrastructure and legal readiness.

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9. The Hungarian Landscape: Research and Regulation

• ZalaZone test track: One of Europe’s most advanced self-driving testing centers, located in Zalaegerszeg.

• Regulatory environment: Currently lacks full legal framework for Levels 3 and up.

• Research: Hungarian engineers and startups are increasingly active in the autonomous mobility space.

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10. Conclusion

Self-driving cars are no longer futuristic dreams — they are a technological reality, advancing every day. The combination of sensors, AI, and real-time decision-making creates reliable, high-precision driving systems.

Although full autonomy is not yet mainstream, the next 5–10 years will bring major changes that could transform traffic safety, efficiency, and sustainability