▁Cord uro ys ▁are ▁cheap ▁and ▁easy ▁to ▁construct ▁and ▁quick ▁to ▁deploy ▁or ▁re loc ate . ▁ ▁They ▁are ▁commonly ▁used ▁for ▁ped est rian ▁access ▁paths ▁and ▁light ▁duty ▁veh icular ▁access ▁ways . ▁ ▁They ▁naturally ▁conform ▁to ▁the ▁shape ▁of ▁the ▁underlying ▁beach ▁or ▁d une ▁profile , ▁and ▁adjust ▁well ▁to ▁moder ate ▁er os ion , ▁especially ▁long sh ore ▁dr ift . ▁ ▁However , ▁they ▁can ▁ce ase ▁to ▁be ▁an ▁effective ▁access ▁surface ▁if ▁they ▁become ▁buried ▁or ▁und erm ined ▁by ▁er os ion ▁by ▁surface ▁run off ▁coming ▁from ▁the ▁beach ▁head . ▁ ▁If ▁the ▁cord uro y ▁is ▁not ▁wide ▁enough ▁for ▁vehicles ▁using ▁it , ▁the ▁sed iment ▁on ▁either ▁side ▁may ▁be ▁disp la ced ▁creating ▁a ▁sp oon ▁d rain ▁that ▁acceler ates ▁surface ▁run off ▁and ▁can ▁quickly ▁lead ▁to ▁serious ▁er os ion . ▁ ▁Sign ific ant ▁er os ion ▁of ▁the ▁sed iment ▁beside ▁and ▁under ▁the ▁cord uro y ▁can ▁render ▁it ▁completely ▁in effect ive ▁and ▁make ▁it ▁dangerous ▁to ▁ped est rian ▁users ▁who ▁may ▁fall ▁between ▁the ▁pl anks . ▁ ▁Fab ric ▁r amp ▁Fab ric ▁ram ps ▁are ▁commonly ▁employed ▁by ▁the ▁military ▁for ▁temporary ▁purposes ▁where ▁the ▁underlying ▁sed iment ▁is ▁stable ▁and ▁hard ▁enough ▁to ▁support ▁the ▁weight ▁of ▁the ▁traffic . ▁A ▁sheet ▁of ▁por ous ▁fabric ▁is ▁laid ▁over ▁the ▁sand ▁to ▁stabil ize ▁the ▁surface ▁and ▁prevent ▁vehicles ▁from ▁bog ging