plotfollow3 adds a new trajectory to an existing graph.plotfollow3 adds a new trajectory to an existing graph.
plotfollow3(cflist, vehicle, uf, kf, ub, leff, t4)contains information about the lead vehicle, a list
a vehicle identifier, a number
speed (mph) of the following vehicle at time t0, a number
density (vehicles per mile, vpm) of the following vehicle at time t0, a number
breakdown speed (mph) for this trajectory, a number
effective vehicle length, a number.
upper range of plot, a number