Method and equipment for motorway control

A method concerning systems for access control of traffic at motorways and larger roads, where the access flow is controlled by information means, which directly or indirectly influence the access travel of the cars, and where the flow size is determined considering the flow size on the motorway, and where cars (A) from the access road interact with cars (B, C, etc) on the motorway while weaving together the respective flows, comprising;

• limiting the flow of A-cars on the access road by a given target value, an allocated ration, which is related to a target value for the motorway flow,
• dynamically correcting the said ration based on at least one of the following (a) and (b);
• a. upstream measurements of traffic flow on the motorway, with a correction determined by the deviation between the said flow target value and said measured value, and where the said upstream measurement site is positioned a distance L1 from the access weaving zone, where L1 is that far, that flow-corrected access cars reach the motorway in time for weaving with those motorway cars, which have caused the flow correction, and where a target value for L1 is L1 ≧v2/a, where v is an applicable velocity value for the motorway and a is an applicable acceleration value for the access, and the qoutient v2/a is covering (is larger than) the corresponding quotient of velocity and acceleration values for most of the applicable traffic situations,
• b. at upstream exit, measurements on cars, which indicate exit, a roadbased equipment, which register information about the cars indicating exit, said information is used for estimating a correction of the downstream access flow, and the traffic density in the right lane of the motorway, on a distance L2 closest upstream the weaving zone for the access, where L2 is less than L1, is determined within a limit in accordance to that access flow, which is estimated for the weaving together with the said motorway traffic, including determination of target values for gaps between motorway cars, where said target values give a density between cars on the motorway, which seen over the corresponding access flow time period for two consecutive (A)-cars, is corresponding to an added gap for those motorway cars, giving space for at least one car, an access car.