Each day in the United States, approximately 9 people are killed and more than 1,000 injured in crashes that are reported to involve a distracted driver. 1 Distracted driving is driving while doing another activity that takes your attention away from driving.
This is called the post-void residual. The bladder has a approximately 500ml capacity. You should feel a desire to void at ~250ml. Urinary retention is measured by using a special type of ultrasound (bladder scan), or by inserting a bladder catheter and measuring how much urine comes out. I'm a 4th year US med student. On one of my urology rotation I asked the Sr. resident this exact question.
Under normal circumstances, the average capacity of an adult bladder, both male and female, is between 400 and 600 milliliters, or between 13 and 20 ounces, according to WebMD. Other sources give an upper limit as high as 1,000 milliliters, or nearly 34 ounces.