Brussels is a "30 city". This means that the speed limit in the capital is 30 km/h for all road users. Exceptions to this rule are certain major roads (where the speed limit could be 50 or 70 km/h, look out for speed limit signs) and residential areas, where the speed limit is 20 km/h. These speed limits apply to all road users (cars, vans, trucks, motorbikes, mopeds, buses, bicycles, scooters, etc.). Only trams, emergency services and snowploughs are not subject to the new speed limits.
The entire Brussels-Capital Region is a low emission zone. This means that the most polluting vehicles are not allowed to drive here. The regulations apply to passenger cars, vans up to 3.5 tonnes, buses and coaches. Whether they are registered in Belgium or not. Not sure if you can enter Brussels with your vehicle? Check it out on lez.brussels.