Taxi drivers all over the world seem to belong to a similar breed. The relatively honest few are usually very new to the business and have yet to be completely corrupted. However, there are still some veteran taxi drivers who remain ethical and honest, but finding one is like the needle in a hay stack or has the same probability as winning a lottery. And in that regard, I am lucky enough to have won the lottery at least once in my life so far!
As I recalled, 20 some odd years ago, NYC taxi drivers at Kennedy Airport (JFK) routinely over-charged passengers up to 10 times the metered fare by pre-negotiating a fare before allowing the "non-suspecting" passenger board the taxi (Particularly targeting the Japanese and those with the "East Asian" look because Japanese were perceived to be the affluent travelers during that time). Soon after, the NYC Taxi & Limousine Commission's (TLC) instituted a fixed fare for the trip from JFK to Manhattan. The current taxi service from JFK to Manhattan fixed fare is US$50.00 (Plus the "expected by practice, pending on the service & the passengers' generosity, but not required by law" tip of 10 to 15% vs. the 15 to 20% expected at restaurants by the waiters) for the average 25-mile or about 40Km trip. At every airport taxi boarding stand, a dispatcher hands the passenger a card with the taxi's "medallion number" (ID) and instructions for reporting abuse and dishonest conduct to the TLC. This practice also prevents the driver from refusing the fare/destination. This fixed fare system has literally stopped all of the fare abuses and the use of tampered meters by dishonest taxi drivers from JFK to Manhattan.
"Black cars", as they are called in NYC, are licensed and fully insured fleet of dark color vehicles (Hence, the nickname "black cars"). Black cars are either wholly owned or serving as individual subcontractor to a privately owned car service company. Black car service and the drivers, like the medallion taxis, are also regulated by the NYC TLC. Black car fares are not metered and therefore not subjected to meter tampering. Upon receiving a call from a potential passenger, the black car company dispatcher, based on distance and other details from point A to point B, will quote the fare amount along with the black car number and time the car will arrive for the pick up. The caller can either accept the quote and agree to the pick up, or reject it and call a different car service. Black cars will also provide long distance service that regular taxis cannot due to complex regulations. Therefore, black cars are safe and reliable, unless you run into one soliciting you and you allow it to pick you up on the street, in which case, both the driver and you are violating the law. Black cars can only pick up passengers by pre-arranged appointments. NYC has a third type of somewhat illegitimate car service called "gypsy cabs". As the name implies, that's another story all by itself.
Getting into a soliciting "black taxi" in China may be extremely risky. In recent years, I have witnessed TV news reports of black taxi passengers being driven to a certain city's "no-man's-land", except for the driver's accomplices, then forced to strip, hand-over all valuables (including the cell phone, of course) and finally being left in the dust by the perpetrating gang.
Proven successful methods against fare abuse such as fixed fares for applicable routes, mandating the manufacture, installation and inspection of "tamper-proofed" taxi meters, and erect visible, easy to understand multi-lingual signage/charts at major locations of a city to show different public transportation choices and typical respective fare charges between frequently traveled destinations are examples that can greatly discourage the use of dishonest tactics by unethical taxi drivers throughout the world.