Chase Scenes

Hazards happen on initiative count 20. They're harder to avoid the further forward you are, and if you're further back, you might be able to find another route.
Adjacent spaces can reach one another. If you don't do anything except run on your turn, you have advantage on that turn's hazard. 
Failing a hazard knocks you back a space. Greatly passing a hazard moves you up.
You can exert yourself with an athletics check, but failure could be really bad...
Be creative! 
# Just the one swan, actually
# City Guard
#Barrels or crates
# Fruit cart knocked to the floor
# Sudden turn
# Brick wall
# Fence 
# Ditch or pit
# Canal
# Pedestrian group
# Merchants, loading crew, workmen
# Carriages and carts
# Gap in fence
# Through a building
# Gravel, cobbles, paving
# Two guys with a sheet of plate glass or a painting
# Carpet vendor, blankets, cloth tent
# Mothers.
# Large stretch of water, boats near a bridge
# Roll twice in quick succession