  The two phase model for vehicular traffic flows recently appeared in
\cite{goatin2006aw} and \cite{BenyahiaRosini01} is endowed with a point
constraint on the flow to allow for the modelling of phenomena such as the
effects of toll booths along a road. We describe in this paper two Riemann
solvers for this model upon which an ulterior study of the cauchy problem
should rely.
