Helmet obligations and other safety laws along the Danube cycle path
There are different statutory provisions in each Germany, Austria, Slovakia and Hungary. If you plan to cycle the Danube exclusively along the German riverside, there is no need to wear a helmet. Just make sure you own the required lightning on your bike.
In Austria, however, children under the age of 12 are obliged to wear a suitable cycle helmet, even if they are being accommodated by an adult on the bike or a bike trailer. Adults do not have to wear a helmet.
If you fancy cycling the Slovakian Danube, beware always wearing a helmet out of town. Children under the age of 15 years are even obliged to wear their helmets in built-up areas. Also everyone cycling whilst poor visibility is bound to wear a safety vest or reflective clothing.
This last point also counts for Hungary. During the night time or poor visibility you are obliged to wear a safety vest or reflective clothing, though in Hungary you’re not being forced to wear a helmet.