More than two-thirds of drivers shun parking spaces which require payment by phone, a study has found.
Some 70% of motorists say they are more likely to keep searching for a space rather than park in one where using their mobile to pay is mandatory, an AA poll of 16,500 drivers has revealed.
Despite their fondness for using cash, almost two-thirds (64%) of drivers say it is often a challenge to find the right coins for parking, with many machines not giving change.
An AA study published last month found that more than one in five UK councils had not converted all their parking ticket machines to accept the new £1 coin, which entered circulation in March.
The motoring organisation warned that drivers embarking on trips to popular tourist destinations from Devon to the Scottish Highlands risk being hit with hefty fines because of the out-of-date infrastructure.
Many councils told the AA they intended to introduce new pay-by-phone systems, but AA head of roads policy Jack Cousens warned that this could create further problems.
He said: "Parking in town centres can be troublesome at the best of times.
"Not only can it be a struggle to find a space, but now when you do find one you may be required to talk to an automated system to pay the charge - not ideal if you have an appointment or just want to get in and get out quickly.
"More than half of drivers (52%) don't care how they pay, as long as it is easy to do so."
Mr Cousens said putting administration fees on parking, not yet accepting the new £1 coin, having to enter registration numbers and failing to provide change are stumbling blocks which "struggling high streets cannot afford" if they deter potential customers.
He added: "All providers should make it easier to pay for parking. Not everyone has a smartphone to pay via an app and not everyone is keen to talk to a robot to pay for an hour's stay. For the elderly and low income drivers, pay by phone feels almost discriminatory."