Not sure how it works elsewhere in the UK, but in London the cab drivers have to take an in-depth course called 'The Knowledge' which covers street routes, alternate routes during street closures, commercial destinations, etc. See some sample questions : http://www.taxiknowledge.co.uk/mock.html
This is majorly helpful beyond usual satnav use case. Eg, to get dropped off during high-traffic area, the cabbies will know well the surrounding streets and at your request can drop you off in a reasonable place 1-2 blocks away, for much less time and expense.
This is majorly helpful beyond usual satnav use case. Eg, to get dropped off during high-traffic area, the cabbies will know well the surrounding streets and at your request can drop you off in a reasonable place 1-2 blocks away, for much less time and expense.