Limited speed, everyone benefits

Driving at 30 km/h is the general rule in Brussels. The exceptions: on certain major roads, the speed limit is 50 or 70 km/h. In a 'woonerf' (residential zones), the speed is limited to 20 km/h.

By car, van, lorry, motorcycle, moped, bus, bicycle, scooter: everyone must respect this speed limit, it's the highway code. The only exceptions are trams, emergency/priority vehicles in the exercise of their emergency mission, and snow ploughs.

The benefits of the 30 km/h city:

• fewer serious accidents
• reduced braking distance
• a better field of vision
• reduced severity of accidents for everyone
• less noise
• better cohabitation between the different road users

The faster you drive, the longer the braking distance becomes:

• At 30 km/h, it takes 13 metres to stop, namely 8 metres to react and 5 to brake
• At 50 km/h, it takes 26 metres to stop, namely 14 metres to react and 13 to brake

26 metres corresponds to the length of 6 parked cars. That's enormous in a city.

Speed has a major impact on the kinetic energy released during an accident, this energy being proportional to the vehicle's mass and the square of the speed (E = 1/2 MV²).

If we compare the force of an impact to falling from a building, it becomes evident that speed plays a crucial role in the severity of accidents.

An impact at 30 km/h corresponds to a fall from the 1st floor. An impact at 50 km/h is equivalent to a fall from the 3rd floor, whereas if it occurs at 70 km/h, the impact represents a fall from the 6th floor.

The risk of death for pedestrians is thus five times higher at 50 km/h than at 30 km/h.

In urban areas, the travel time for a journey combines the time in motion and the time spent stopped or waiting. Unpredictable traffic elements, such as traffic lights, intersections, and congestion, keep the average speed between 18 and 24 km/h during the day, and at 30 km/h at night.

A comparative study carried out on 12 typical routes in 2019, 2020, and 2021 shows that the 30 km/h speed limit did not have a significant impact on travel times. These remained overall stable on each measured route, regardless of the time of day (peak hour or off-peak).

In urban areas, distractions on the road are numerous, whether related to static obstacles or moving road users. The dangers multiply and are often unpredictable.

Unfortunately, a driver often only thinks about adjusting their driving when they visually perceive a danger. However, as the vehicle's speed increases, the field of vision gradually narrows.

At high speeds, vision focuses on a single point straight ahead, creating a "tunnel vision" effect. The field of vision of a stationary person is 180°. According to measurements taken by Brussels Mobility during a virtual experiment, this field reduces to 102.17° at 30 km/h and to 75.46° at 50 km/h.

In built-up areas, near schools, in residential or encounter zones:

• Speeding up to 10 km/h above the permitted limit will cost you €53.
• Speeding more than 10 km/h above the permitted limit will cost you €53 + €11 for each additional km/h.

Generally speaking, you also run the risk of having your driving licence withdrawn or revoked from a speeding offence of 20 km/h above the permitted limit and risk being summoned before the Court for an offence of 30 km/h.

What if a guided walk in your municipality allowed you to discover the benefits of the 30 km/h city? The non-profit organisation Good Planet invites you to become a mobility investigator. Equipped with a sound level meter and a speed radar, you will see how reducing speed makes the city safer and more pleasant to live in.

This free workshop, lasting 2 hours, is open to everyone aged 9 and over: families, citizens, young people, organisations, etc. It can take place in one of the 19 municipalities of Brussels, as chosen. The group size can vary between 4 and 8 people.

More info: Opens in new windowhttps://goodplanet.be