In　contrast　to　the　fruitful　results　in　saturated　control　of　ordinary　differential　equation　(ODE)　systems,　there　are　few　related　studies　for　hyperbolic　partial　differential　equation　(PDE)　systems.　This　paper　focuses　on　the　saturated　boundary　feedback　stabilization　problem　for　the　Lighthill-Whitham-Richards　(LWR)　traffic　flow　model,　in　which　a　variable　speed　limit　(VSL)　device　is　applied　at　the　downstream　boundary　in　the　presence　of　actuator　saturation　and　a　saturated　boundary　feedback　controller　is　proposed　to　drive　the　traffic　density　to　the　steady　state.　By　employing　the　Lyapunov　function　method　along　with　a　modified　local　sector　condition,　sufficient　conditions　for　ensuring　the　local　exponential　stability　of　the　LWR　traffic　flow　system　are　developed　in　C1-norm.　Remarkably,　the　proposed　sufficient　conditions　establish　a　relationship　between　the　control　gain　and　the　region　of　exponential　stability　(RES),　and　thus　the　maximal　RES　can　be　determined　by　introducing　an　optimization　criterion.　Lastly,　numerical　simulations　are　performed　to　verify　the　effectiveness　of　the　theoretical　results.(c)　2023　Elsevier　B.V.　All　rights　reserved.