▁the ▁James ▁D . ▁P flug er ▁Ped est rian ▁and ▁B icy cle ▁Bridge , ▁situated ▁ ▁to ▁the ▁east ▁of ▁the ▁L amar ▁bridge . ▁ ▁Design ▁ ▁The ▁L amar ▁Bou lev ard ▁Bridge ▁is ▁an ▁open - sp and rel ▁deck ▁arch ▁bridge ▁made ▁of ▁pou red - in - place ▁rein for ced ▁concrete . ▁It ▁cross es ▁the ▁Colorado ▁River ▁with ▁six ▁identical ▁ ▁sp ans , ▁supported ▁by ▁five ▁concrete ▁pi ers ▁on ▁the ▁river ▁bed ▁and ▁by ▁concrete ▁ab ut ments ▁at ▁the ▁ends . ▁The ▁deck ▁car ries ▁four ▁road way ▁lan es , ▁fl ank ed ▁by ▁a ▁side walk ▁and ▁metal ▁bal ust rade ▁on ▁either ▁side . ▁The ▁pi ers ▁( origin ally ▁visible , ▁but ▁now ▁largely ▁sub mer ged ) ▁and ▁ped est rian ▁guard rails ▁show ▁Art ▁Dec o ▁details , ▁such ▁as ▁vertical ▁fl uting , ▁which ▁indicate ▁the ▁period ▁of ▁the ▁bridge ' s ▁construction . ▁ ▁The ▁pi ers ▁stand ▁on ▁spread - foot ing ▁found ations ▁rest ing ▁on ▁lim estone ▁bed rock . ▁Each ▁span ▁rest s ▁on ▁two ▁parallel ▁concrete ▁segment al - arch ▁rib s , ▁each ▁ ▁wide ▁and ▁ ▁thick , ▁rising ▁to ▁a ▁clear ance ▁of ▁ ▁above ▁the ▁spring line . ▁A ▁series ▁of ▁sl ender ▁vertical ▁columns ▁r ises ▁through ▁the ▁open ▁sp and rel s ▁to ▁support ▁smaller ▁longitud inal ▁arch es ▁and ▁trans verse ▁floor ▁be ams ▁immediately ▁beneath ▁the ▁deck . ▁The ▁floor