Local runners take to the causeways over the Indian River for a bit of “hill work” on the otherwise flat Space Coast. Among the arcs over the water that are fun and scenic, the Melbourne Causeway is the most popular for running. It’s part of FL-192, so there is some traffic, but runners are protected by a barriered sidewalk. Both sides of the causeway are endcapped by nice waterfront parks. On the west end, runners can extend the route through Front Street Park and the Crane Creek Promenade. From here, an out and back is about 4.5 miles.
Note: the Eau Gallie Causeway (SR 518) and A1A bridge do not have protected sidewalks (but the Eau Gallie Causeway has a nice wide shoulder). Much of the Merritt Island Causeway does have a separate, protected pedestrian bridge.