By Geoff Adams-Spink
Age & disability correspondent, BBC News website
The display is clear but accuracy can be a problem
A satellite navigation system made specifically to assist disabled drivers has been made by a UK company.
Gowrings Mobility - a specialist in adapted vehicles - is marketing the BB Nav, developed by Navevo.
The system contains a database of Blue Badge parking bays, accessible toilets, disabled-friendly petrol stations and accessible accommodation.
It covers 150 major towns and cities around the UK including all of the London boroughs.
"Many disabled travellers worry about the uncertainty of not knowing where to park... and consequently do not venture further afield than their own local area," said Janet Seward, sales and marketing director at Gowrings.
"We want to make disabled travellers' lives and journeys much smoother, easier and more spontaneous."
The BB Nav grades car parks according to their level of accessibility and also has the location of more than 10,000 on-street parking bays.
The device is also programmed with the varying parking regulations for Blue Badge holders as they move from one local authority area to another.
Other "points of interest" (POIs) include accessible beaches, shopping facilities, toilets and hotels.
In practice, the BB Nav delivers a lot less than it appears to promise.
The unit is small and slim - much like other in-car GPS systems.
But unlike other satnavs that rely on finger operation, the BB Nav has a telescopic stylus that is housed in the body of the device.
Something so small and fiddly can and probably would be easily lost in a car.
The on-screen keyboard is too small to allow it to be programmed by all but the most slender of fingers.
The system had a problem finding some parking spaces
And the display fonts are so small that older motorists will be reaching for their reading glasses.
On the plus side, the display is large, the map easy to read and all side roads are helpfully named.
The default female voice is clear and crisp but does have a tendency to repeat itself too often.
When tested in the outer suburbs of North-West London, the BB Nav was disappointing and - at times - mystifying.
It failed to locate on-street parking bays on Bridge Street in Pinner.
When asked to find an accessible toilet in Ruislip, it found its way to a residential street of pre-war, detached houses with not a public convenience in sight - accessible or otherwise.
And when accessible accommodation in Harrow was requested, it located a Hilton hotel in Wembley but directed the car to industrial units close to the football stadium.
When Navevo - the makers of the BB Nav - were approached to comment upon the problems encountered, they referred the issue to The Pie Guide, the company that provides the data for the device.
Mike Hudson, data manager for Pie Guide, explained that the data on parking bays came from local authorities in a variety of formats, the quality of which was variable too.
Referring to the absence of the parking bay in Pinner, Mr Hudson said: "I suspect that the council has not provided the data to us - hopefully it will be picked up in a forthcoming update."
He said that the hard-to-locate accessible toilet in Ruislip was "troubling" and that it would require further investigation.
Data on accessible hotels was, he admitted, "not great".
The information comes from a variety of sources depending on the part of the UK being searched.
And not all hotel chains submit to the verification process which they would have to pay for.
"There is no one, single data source to which we can go and extract this information," said Mr Hudson.
Data updates are planned for the future but are still the subject of commercial negotiations between Navevo and Pie.
For a product costing just under £200, it seems a little rough around the edges to justify the price tag.
Given its shortcomings in terms of usability and accuracy, disabled motorists might be better off waiting for other satnav suppliers to install a set of disabled-friendly POIs.
Of those contacted, Garmin said providing useful information for disabled drivers was already being considered.