Thousands of lorry drivers are at risk of becoming ill due to a “shameful” lack of toilet facilities available on UK roads.
One in ten said they had been unwell when unable to locate toilets while working on motorways across the country, the Unite union added.
A study of 1,700 drivers from across the UK found around 75% had experienced situations where they needed to use the toilet only to find none available while others said it was common for facilities to have restricted opening hours since the Covid pandemic.
The union said the statistics showed workers were repeatedly being denied “toilet dignity”.
One in ten said a lack of access to toilets had resulted in them developing a medical condition.
Many others reported problems with cleanliness and restricted opening hours at toilets at service stations and truck stops, and only one in five said they were always given access to customer toilets.
Unite national officer Adrian Jones said: “It is disgraceful that lorry drivers are being made ill by being denied routine access to toilets.
“A lack of access to toilets is a key reason why workers leave the industry, especially if they have a medical condition.
“The industry will never become more diverse and be attractive to new entrants until this problem is resolved and toilet dignity becomes mandatory.”
Scotland is home to more than 30 truck stops and motorway service stations, though most are located in the central belt and Borders.
A Department for Transport spokesperson said: “Hauliers are vital to this country and deserve a good supply of facilities that are safe and clean.
“That’s why we’re investing over £52m to improve roadside facilities, enhance security and improve welfare for HGV drivers.
“We also continue to encourage private providers to ensure all their facilities are always up to an acceptable standard.”