I really like your design, especially the solid color shows how well it will duplicate.
However, your design is currently in third because the top two do a better job of conveying what we want to say: namely somewhere to walk and bike which connects the city to the suburbs.
#151 really shows the transition from suburbs (trees) to city (bridge). The Ben Franklin Bridge is an iconic symbol in our area of connecting to the city because it links us with Philadelphia.
#135 has been a favorite because of the characters, it's one of the only top designs that actually shows walkers and bikers. The building signify the city.
On both, the text and logo are both large and easy to see/read as well.