I don’t know about a sensor that could give you distance+motion at the same time. What do you have in mind?
Maybe you could use accelerometers, gyro sensors, proximity sensors and/or ultrasonic sensors. But I think it depends on how are you going to sense the signals.
Could you be more specific about the project you have in mind? I think that will help us to give you more ideas.
Most of what I've seen available for tracking motion and distance would fall into the human interface category. Not sure if it's what you're looking for but there are things like these:
Adafruit has these, but from the description they're only good for 5cm and appear to be mostly to register swipes in three axis. Pimoroni Skywriter HAT - 3D Gesture Sensor for Raspberry Pi ID: 2325 - $20.95 : Adafruit Industries, Unique & fun DIY el…
I've seen a few lighter duty modules like this one that usually consist of a combination of either a few optical or ir distance sensors SparkFun RGB and Gesture Sensor - APDS-9960 - SEN-12787 - SparkFun Electronics
I think parallax makes a similar board also.
I have contemplated trying to hook up a leap motion controller
Hope that helps :-)
Thanks for the feedback! For a current project need some flexibility in detecting people and pedestrian traffic in a public setting. A distance range of roughly 3-15ft would be ideal. I know ultrasonic sensors are useful in this range but, as mentioned, only detect distance. Will check the links you mentioned.
I'm wondering if using more than 1 ultrasonic sensor to interpolate motion and direction might work?