Road line traffic control is a telematic system consisting of gates with variable mandatory or prohibitory traffic signs above or beside the road. Detectors monitoring the traffic flow characteristics, such as traffic density, intensity, or average speed are also part of the system. The gates are approx. 1,000 to 1,500 metres apart.

The road line traffic control system gradually decreases the speed or alters the organization of traffic into lanes so that the movement of the lines of vehicles is as smooth and safe as possible. As vehicles may safely drive with shorter following distances at lower speeds, the traffic flow is better harmonized. The result is that more vehicles may pass through the given section, more continuously and faster (although the actual speed is lower). Road line traffic control increases the smoothness of the traffic flow and reduces the probability of queue formation and their potential size.

If all drivers maintain the SPEED REQUIRED by the variable traffic signs, the appropriate SAFE FOLLOWING DISTANCES from other vehicles, FLUENT DRIVING STYLE WITH MAXIMUM CONCENTRATION (without needless stopping, slowing down, overpass attempts, etc.) then all of them will pass the section faster and more fluently.

If just one driver unnecessarily disturbs the fluency of driving or stops, all drivers behind that one have to stop. Repeated starts of all drivers takes much more time than continuous fluent driving. Watching an accident scene or other curiosities, e.g. on the other side of the motorway, also means holding all the drivers in the queue back.

With the traffic density of 3,000 vehicles per hour on the D1 motorway, ONE SINGLE SECOND OF USELESS DELAY taken by each driver to check the impact of an accident EXTENDS THE QUEUE BY AN ENTIRE HOUR.

Road line control gate

Road line traffic control is built in sections where traffic intensity increases and queue formation occurs regularly and repeatedly. The road line control on the Prague Ring Road consists of a total of 34 gates with variable traffic signs and 6 variable message signs. The road line control at the point where the D1 motorway enters Prague consists of 11 gates with variable traffic signs and, apart from the existing two, two new variable message signs.

Road line control is also partially installed on the D1 motorway between Ostrava and Bohumín and at most tunnels on Czech motorways.