Using Motion Sensors to Detect the Direction of a Object

Is any known way of using motion sensors to detect the direction that a object is traveling? I suppose that if you hook up 3 sensors you may be able to detect it. Any ideas? Thanks

What kind of object? Where is it in relation to your sensor? What kind of sensor?

Shpaget:
What kind of object? Where is it in relation to your sensor? What kind of sensor?

It would be a person. The object would be about 10 cm from them. I need it to detect whether the person is walking forward or backwards.

Do you have some sort of hallway or door frame through which you can restrict the movement and force individuals to go one by one?
If yes, can the sensors be placed on both sides of the door frame?

It would be helpful if you started volunteering information. Describe your needs in detail.

Draw a diagram. Include some dimensions. If the object is only moving along a line, you can detect whether it is moving towards the sensor or away from it.