In China, we can always see the cars drivers waiting on the roadside because of the car crashes or changing the tires or taking an emergency phone call. But most of them don't wear a vest with reflective tape. It will be very dangerous without wearing it especially in the darkness.
Now many countries have already issued laws to demand drivers to put a vest in the car. For example, Germany has issued a law in July 2014. It says, a fluorescent yellow or orange safety vest is necessary in each car. The bright material of safety vests can increase the high visibility whether in daytime or night. So when drivers come across the vehicles breakdown or car accident or other unexpected cases, had to wait on the road for help , then they can wear this kind safety clothing. It can help other passing by drivers see them clearly and protect them from the danger. In addition, more and more car sellers have already brought large quantity of the basic hi vis vests with their car brand logo on it and give it to their customer as a gift directly.
Drivers, do you have a reflective vest in your car? If not, why not buying several vests in your cars in case of unexpected need.