Denver. Traffic Operation Big Switch brings some snarls. Post Je 13, 1955 P 1 'Switch' derails traffic at 14th and Market. (Picture). Post Je 13, 1955. p.1 Bruce terms conversion to 1-way system success. PEN Je 15, 1955 p.16 city crews begin painting lanes. RMN Je 16, 1955 p.44 Newton appoints new city parking director. Post Je 20, 1955 P.10 Skip-stop bus system to end; new zones set. Post Je 21, 1955 P 1