You are experiencing a urinary incontinence and this may result from a neurologic injury, strokes, multiple sclerosis, and physical problems associated with aging.
Incontinence is treatable and often curable at all ages.
It sounds as you are experiencing a total incontinence, when the person is always leaking urine.
Usually, happens when the sphincter muscle no longer works.

Visit a urologist!

This started shortly after being hit by a car. At first it was only occationaly at night but then progressed to daytime incidents. I have been to doctor after doctor about my bladder disorder and finally about 25 yrs ago a doctor had me start weearing protection. 8 years ago I decided to go to cloth diapers and plastic pants. I really don't mind wearing diapers now but it took a long time to get used to.

A spinal injury due to a car accident can interfere with the nerve signals involved in a bladder control, causing the urinary incontinence.
Some physicians think that a type of drugs known as anticholinergics can be beneficial in such cases.

Best wishes!

I have a spinal cord injury and have had for the last 31 years. I'm a female but what I found effective for many years was plain Ditropan not the Ditropan XL (XL didn't work for me). Then I had to switch about 5 years ago to vesicare which was working just alright. So about 3 years ago the Doctors put an Implant called Interstim by Medtronic into my lower back on the right side that is a Neurostimulator for the Sacroiliac nerve and the spasms. You can google Medtronic and then talk with your urologist about it.
Good Luck

I'm sorry it's not the Sacroiliac it's the sacral nerve.