What!!?!
A guy who drives around all day usually working to a brutally tight schedule with no immediate access to a toilet? And in an industry with a median age of 55yo and hence likely a weaker bladder. Probably rushing to get to his next job in the delivery window before he worries about finding a loo (and possibly occasionally misjudges it or hits unexpected traffic/roadworks).
I drive trucks for a living and being caught short is one of my biggest issues/fears, which is why some amazon drivers are literally shitting in buckets in the back of their vans. The vast majority of the public work in environments where the toilet is less than a minute away and they're not being tracked for every minute and potentially penalised financially through loss of bonuses when late. They generally have no idea.
When I'm desperately needing a wee whilst sitting in bad traffic in the town centre....well, it's a fucking nightmare. You can't just pull into McDonalds or any car park because most have height restrictors and you need a whole row of spaces to park. And if you're lucky enough to find somewhere you can be assured some helpful soul will report you to your employer for parking there or take photos and post them online tagging the company.
You can't even plan ahead because with how hot it gets in trucks you need to stay hydrated and it can come on quick - in our truck without a/c it was the same temp as outside (34°C) when driving with windows down last summer and was 44°C when pulled up onsite with windows closed to prevent dust ingress from the shovels thundering past - thankfully this is usually only necessary for around five mins. You need to drink lots of water to stay hydrated and safe to drive in that heat when you're wearing work trousers, plasticky hi viz, and a long sleeved shirt underneath (site safety requirement). You're usually sitting right above the engine.
I can't even keep an emergency bucket in the back as I drive construction vehicles like mixers and tippers that don't have an enclosed space at the rear. How I envy the men sometimes and how easy they can take a tiddle!
A combination of stopping to find a toilet and then hitting unexpected traffic could see my concrete setting in the drum permanently and ruining it to a cost easily over £10k when you consider downtime. A lot more if your client has a loss of earnings clause and can charge back the wages for the workers they now have to pay for sitting around unable to work due to no materials delivered. I'd quite honestly prefer to piss myself in that situation and have the seat reupholstered rather than pay for a new drum, the downtime, and maybe client losses.
So if I was a bloke I'd absolutely piss against a tree in a moment of desperation, and being self employed I'd tell your husband to fuck right off without a second thought. No driver wants to urinate in public and most workers in other sectors have the privilege of never needing to.