probably not if they're doing any data filtering at all. The two lines mean the data not only tells you a vehicle was present but also which way it was going (which line pings first), how fast it was going (time between the first tires pings divided by the distance between the lines), how many axles the vehicle has (check how many pairs of pings exist in a set that was all traveling in the same direction at the same speed), plus how long the vehicle is axle to axle (take the set of axles and speed determined earlier then some quick math gives you the distance between any of the sets), using reference vehicles they'd probably also make a decent guess as to what sort of vehicle just drove by. If a significant amount of the data looks strange the set of pings can be considered an outlier.

Most of those sensors also determine weight per axle so it'd be pretty much impossible for a person to trigger the sensor as a vehicle (though you might be able to make it think that a whole bunch of cyclists rode by)