Why should we not throw away plastics carelessly on roads?

Plastics being non-biodegradable pose a serious threat to our environment. Their safe disposal is a big problem. People often carelessly throw away plastics. They also do not get mixed with the soil and do not get decomposed. Stray animals often eat plastics along with their food, suffocate and die. Polythene bags get stuck in the drains and clog them. It leads to spilling of sewer water onto the streets.