The idea, named SpeedToll is based on elapsed time between control points and is in essence simply the calculation of driver's speed between entry and exit points by the direct application of classic average speed definition: the ratio between the distance and the time spent. 
         It's sufficient that at entry point we also make a record of entry time, so that at exit point we know how much time the driver spent between the two points. This entrance time record may be made in a few different ways: print entrance time in entry ticket, record car's license at entry point (if there is computer integration between control points and operators at entry point). We may also use the method in conjunction with automatic toll payment systems (ETC). 

        If road section is covered in less than standard time (time it would take between control points following speed limits along the way) we can say that driver has violated speed limit and we could charge him a fine. Those fines could be collected immediately or post processed by transit departments and charged later to drivers (if we use the car license recording option). This would be a remarkable way to enforce speed limits, but in next paragraph we'll see there is an even better way than directly charging fines (that would generate a licensing fee for us based on fines charged by this method). 

        Let's examine now toll overprice that's much more effective and is our recommended procedure, because it allows immediate punishment of excess speed and at the same time keeps intact the current controls and fines, now with a higher rate of success. The concept is a toll that is based not only on the distance covered but also on the relative speed it has been covered. 
        Overprice rules (tables or formulas) may be adjusted to the level of speed enforcement we want to ensure. And again, as we are not charging speed fines but rather the toll only, fines remain possible. Possible and easier, as the expected speed limit respect will make easy to identify faster vehicles. In essence, SpeedToll takes care of the mass and makes easy for road patrol to pick up exceptions. 
 
        Control may be broken in sections in order to enforce specific speed limits in critical paths (dangerous road sections demanding very low speed or very good road sections that otherwise would be covered at excessive speed). 

        Collection may be done at each intermediate point or only in selected ones and on exits, depending of management convenience. 

        The method naturally permits differentiation parameters for different categories of vehicles, as cars, buses, trucks, motorcycles, etc. 
        Besides having different prices, each category might have different speed limits, a very convenient safety enforcement feature. 
        For each category, specific price and standard times (speed limits) apply for 
each controlled section. 

        This method may also be used in specific urban ways where an efficient speed control is needed, even if there is not a toll charging. 
        In this case basic toll is zero, but drivers will be charged for speed excess. 

        Drivers don't have an easy way to avoid charges when this method is used. It's not like radar systems and police control that may be noticed by drivers and equipment like radar detectors: fast drivers are always caught. The only way not to pay toll overprice is to make each road section within speed limits, or, in other words in standard time. 
        Drivers  may run faster, provided that afterwards they stop or slow down in order to complete required time. It seems not to be an interesting behavior. Even in this case it's possible to avoid this trick by adding control points in selected stops. 
 
        We imagine to license SpeedToll to road operators, for use in roads and even urban highways, accordingly with particular circumstances. 

        As we can see, concept is very simple, but absolutely efficient in respect to what it intends to do. Significant social and behavioral benefits are generated. 

        To have this method effective, it's necessary political support, legal permission,  commercial agreements with road operators, auditing provisions, technical support contracts, and mass marketing advertising all the benefits of it's adoption, like reduction of accidents in controlled road, additional road incomes charged to fast drivers, enforcing speed limits, etc. 

        In order to make this idea operational, we developed an specific software, "TimeCop" that implements all those concepts for immediate use. 
       This software may be easily used in different software and hardware environments, in order to interface with existing user applications and standards.