1 Winston drives his Astin Martin into the charging zone.
2 A camera takes a photograph of his sedan’s license plate.
3 The camera sends analog signals to the city’s Automatic Number Plate Recognition computer system in central London.
4 The license plate data captured by the camera gets compared to a database of license plate owners.
5 The system identifies Winston’s car. He is liable for the congestion charge for this day (about $8).
6 Winston can pay his charge online; by mobile phone text messaging; at self-service machines; by phone; by mail; and at 229 retailers within the zone and 10,000 others nationwide. If he doesn’t pay by 10 p.m. today, he’s liable for an $8 fine (for a total of about $16).
7 If he fails to pay by midnight, the fine is about $130; after 28 days, the fine rises to about $200. Three-time offenders may see their autos towed or “clamped” and be subject to further fines.