Tehran is definitely not the best city to run in. With its busy streets and air pollution you need to chose appropriate time and place for a run. I do have several favourite running routes in Tehran but if you want to go for a long run, the best time is Friday morning. Get up no later than 5am, lace up your running shoes and head out. Then you are free to take any roads, parks or even highways. You even don't need to plan your route in advance. As an architect I'd always like to explore different neighbourhoods of Tehran and running -in addition to all the great stuff brought to my life - is now helping me on doing so.
Here you can see three different routes I took the last couple of weeks. The blue one is 16-kilometre long, the orange one covers 32 km and the yellow one is exactly 25 km. All took me to some parts of the city I had never walked in before. For my next long run, I'm going to take another new route, to explore more of the city I live in.