zipperwrapper: 'zipperwrapper' produces 't-x' trajectory for vehicles...
In PJOssenbruggen/Basic: Tools for Understanding Highway Performance

zipperwrapper produces t-x trajectory for vehicles traveling on parallel lanes that merge at a bottleneck.

1	zipperwrapper(nveh1,nveh2,umn,usd,xstart1,xstart2,delt,tstart,tend,xfunnel,leff,type,browse)

`nveh1`	number of vehicles entering the bottleneck from lane 1, a number
`nveh2`	number of vehicles entering the bottleneck from lane 2, a number
`umn`	start speed (mph) for vehicle in lane 1, a number
`usd`	speed standard deviation, a number
`xstart1`	start location of the first vehicle in lane 1, (feet), a number
`xstart2`	start location of the first vehicle in lane 2, (feet), a number
`delt`	time-step, a number
`tstart`	vehicle crossovers are are permitted below this time, a number
`tend`	upper time range of simulation, a number
`xfunnel`	location where the lane drop is located, a number
`leff`	vehicle length in feet, a number
`type`	TRUE to create plots or FALSE otherwise, a logical
`browse`	to inspect `fixviolation` to inspect plot or FALSE otherwise

The zipperwrapper, a wrapper function for bmfree3, xabparam and hsafe, returns a smooth hsafe rule t-x trajectory for the following vehicle, and critical information. The lead vehicle trajectory is not affected. Passing is not permitted. The input matrix lane contains desire lines for a leading and following vehicle.