For many people waterfront promenades are places to drive to, get out, go for walks (perhaps with their dogs on retractable leads), before returning to their cars to drive home. For a few of us though, waterfront promenades provide a rare opportunity in cities where cars hog the road, to use bikes for transport.
To my mind there are hundreds of places to walk around in big circles with your dog on a lead—like, maybe a park—but there are very few easements of any significant length that can be repurposed as bike transport corridors. We have it all back-to-front as designers of waterfront pathways when we provide better protection and treatment for pedestrians, who generate car trips and dog shit, than we give to cyclists, whose presence on the waterfront equates to less driving elsewhere in the city. See the big picture.
If dawdlers and their dogs feel uncomfortable having cyclists whiz past their ears, the answer might not be a “cyclists dismount” sign. It may be
1. provide a wide enough shared space that any cyclist can steer their way past those retractable dog leads
2. segregate bikes and pedestrians, ensuring the bike route is the nearest to the water and the pedestrians cop all the car fumes (don’t encourage them)
3. get rid of the car park.