The number plate opens the barrier, and every pass is written down

A gated site today runs on cards that get lent out, remotes that get lost and a guard stepping out of the hut to write a plate in a notebook. When somebody needs to know which lorry came in at seven on Tuesday, the answer is in that notebook or it is nowhere. IRIS reads the plate as the vehicle drives in, checks it against the lists the customer has loaded, and decides right there whether the barrier opens. The credential stops being a piece of plastic and becomes the vehicle itself: it cannot be lent, lost or left at home. And every pass is kept with its time, its camera, its photo and its video.

This site spends nine zones saying IRIS does not read number plates, and on those cameras that is true. Plate reading is a feature switched on camera by camera, and it ships switched off. At a car park access gate you turn it on, because that is what it is for. On the camera over a school playground you do not, because there is no need at all: there IRIS still sees a vehicle, not a plate. Every installation decides where yes and where no, and that decision is written down with its date and the person who made it. Every access control tender asks for this feature. What is not common is being able to answer, with a date and a name, on exactly which cameras it is running. Plenty of products read plates; far fewer can show you where theirs is switched on.

Four things, and none of them is “reading a number”. First, the lists: the barrier opens by itself for whoever it should, at the hour it should, and a block list is never masked by a permit list. Second, origin and destination: two reading points and one subtraction tell you how long a lorry really takes from the gate to the dock, which routes repeat, and which vehicles came in and have not left. That is no longer security, it is operations: it measures the congestion everybody complains about and nobody can prove, and it chases nobody. Anyone can sell a barrier that opens by itself; very few can put that number on the table. Third, the access control itself: ten kinds of point — from a barrier to a bollard, or just logging the pass without opening anything — and an opening sequence the customer builds step by step from the web. And fourth, parking: free spaces, occupancy counted by identified vehicles, and an alert when somebody has been inside longer than planned.

What it does not do gets said too. It does not read make or model: it knows the vehicle type and the colour, and when the camera did not see them properly the field stays empty instead of being filled with something that looks real. There is no lane detection either; there is direction of travel and heading in and out, which is the figure that actually exists. The engine decides and records, but it does not move barriers on its own: opening by hand is a separate permission, asks for a written reason and stays in the name of whoever did it. Everything is logged, including the refusals — those are the customer's eight-in-the-morning phone call — and months later you can rebuild why that barrier opened that day and how it was configured back then. It all travels over a single port, 443, and it works with the site cut off from the internet.

A real number plate is not clean, not straight and not well lit. That is why one pass is not one reading: it is dozens while the vehicle crosses the camera's field, and the system treats them as a single pass, because one of them coming out well is enough. Then there is the problem of characters that look alike: zero and O, one and I, eight and B. IRIS keeps a catalogue of fifteen known pairs, switched on one at a time rather than as a block, because they are not all worth the same: when a letter is confused with a digit, the country's format usually breaks the tie; when two digits are confused, nothing breaks it, and that pair ships switched off. And every pair arrives with a real case from the site itself — two plates differing in that one character — or with a note saying none has been measured here. Never with an invented example.

What is not read properly is not stored — but it is not hushed up either. There are five reasons a reading gets discarded — it carries a character that does not belong, it is too short, too long, it has not a single digit, or the system is not confident enough — and each is counted by the hour even when the reading is thrown away. It is the only trace left of it, and it is what lets you see how many are being lost on that camera and why, instead of staring at a counter that only shows the hits. The screen always says how many plates and how many readings out of how many are on show, and with which filters: hiding data quietly is not filtering. And when one access point departs from the general rule to be more permissive, the screen warns in red before saving, because a physical barrier ought to be stricter than a list: one character of slack is the gate opening for the wrong car.