Here are some path markers and "one way" tokens I made from EPVC, Krylon, and acrylic hobby paint.

https://500px.com/photo/239077079

https://500px.com/photo/239077569

Edit: Picture of sidewalk with cards for scale, as requested.

https://500px.com/photo/239077079

They look awesome, can you show them next to the cards to get some scale?

OP edited to add picture of path markers with cards for scale.