So yes, we did blame mother nature for making it so easy for men to pee on the road. But here's another take on the issue which shows that mother nature warns you much before you have no choice left!

Dr. Shweta Narang says, "The first signal that you must void your bladder (urinate) is sent when the bladder is filled up till 150 ml. However, if you don't empty your bladder at that point, the plasticity of the bladder enables it to stretch and the signals disappear. They reappear at about 400 ml and will remain until you urinate. Be warned that if you don't urinate then, the sphincter will give way and you will end up urinating on your person,".

Let's do some calculations.
On average, the bladder fills up by 2ml per minute. The first warning comes at 150 ml and the second comes at 400 ml - which means after 250 additional ml have filled up. This means we have two whole hours before the second signal goes off.

Dr. Amit Arora adds, "Two hours is only when the second signal becomes evident - you still have a good ten minutes (depening on your control) before you absolutely must empty your bladder - it's all about listening to your body."