  In this study, we start from a Follow-the-Leaders model for traffic flow that
is based on a weighted harmonic mean (in Lagrangian coordinates) of the
downstream car density. This results in a nonlocal Lagrangian partial
differential equation (PDE) model for traffic flow. We demonstrate the
well-posedness of the Lagrangian model in the $L^1$ sense. Additionally, we
rigorously show that our model coincides with the Lagrangian formulation of the
local LWR model in the ``zero-filter'' (nonlocal-to-local) limit. We present
numerical simulations of the new model. One significant advantage of the
proposed model is that it allows for simple proofs of (i) estimates that do not
depend on the ``filter size'' and (ii) the dissipation of an arbitrary convex
entropy.
