4th St. / Cedar Ave. / Lockett Rd.

Flagstaff, AZ

  • Diagram of a roundabout at the intersection of N Fourth St, E Lockett Rd, and E Cedar Ave, with nearby schools and college indicated.

    BACKGROUND

    The City of Flagstaff retained MTJ (as part of the AZTEC team) to evaluate the feasibility of a roundabout application at this highly constrained site. The intersection is located adjacent to elementary/middle school, college, commercial and residential uses.

  • Aerial view of a roundabout design with labeled roads and nearby locations including two schools and a college. Roads included are E Cedar Ave, N Fourth St, and E Lockett Rd. The design shows traffic lanes and circular intersections, focusing on roundabout engineering by MTJ.

    SUMMARY

    MTJ Roundabout Engineering developed two geometric designs for evaluation of feasibility. The double-roundabout avoids residential impacts; whereas, the 4-legged roundabout impacts one residence.

    Each design achieves operational, accessibility and safety objectives for all modes – vehicular, pedestrian, and cyclists.

    Design highlights:

    Horizontal designs that minimized adverse impacts to surrounding context

    Designs highlighting safety for all modes

    Sensitivity analysis to reflect accommodation of future traffic growth

Highlights

  • Highly constrained context

  • Multimodal safety priority

  • Minimization of adverse impacts, including residential traffic flow

  • 4-leg and double-roundabout alternatives

Satellite