The delays prevent your code from working properly.
Answer to yourself:
- How many sensors can be covered by one person?
- How do the signals change if one person goes through, goes back, a second person enters...
What you need is a state machine, with states like
empty, one_in, one_through, one_back, two_in
Then determine whether changes in the sensor values allow to determine the new state of that machine, and to count the persons properly.