Blind Cane Sensor

Doing a project involving a smart cane , is it possible to detect moving vehicle with a ultrasonic range finder ?

Define "vehicle", "moving" and "ultrasonic range finder".
You may also want to define "range" and "safety".

so basically i will be having a cane that visually impaired people use to detect things in their surrounding . What i have done is attaching an ultrasonic sensor HC-SR04 on the handle area of the cane to detect object. And this can be done. i will be placing another high perfomance ultrasonic range finder (LV-Max Sonar ) on the bottom of the cane. Purpose of this sensor in mind is to detect a moving vehicle. But i dont know how to program the sensor in such away , when a button is pressed, it can determine the a speed of a vehicle in advance and if the condition is fullfilled in this case (10km/h) ,it will send signal to the vibrating motor which alets the visually impaired users. Sorry for not being specific earlier.

from what direction ? front, left, right ?
how far away ? if you figure a car driving at 25 mph, can stop easy enough when it sees someone in the street.

a car moving at 40 mph needs brake time, and reaction time of the driver.
also, before you walk onto a street with you would want to test if a car is far enough away to have time to react and brake.

or closer than that so you do not enter the street.

what distance is needed for this sensor to have any use at all ?
the speed will cars will dictate distance.

I think ultrasonic is not capable of this feat.
what do police use to detect cars from a distance ?

high perfomance ultrasonic range finder (LV-Max Sonar

has a range of only 6.5 metres.
10kmh-1 is 2.7ms-1, which doesn't give anyone very much warning, even assuming (which you cannot) that every vehicle will return every "ping".

what do police use to detect cars from a distance ?


Sorry, I would like to rephrase. The LV Max Sonar will be near the tip of the cane. Pointing horizontally left or right (depends on country traffic). I would like to have the vibrating motor to vibrate if there is any vehicle moving faster than 10km/h. Is there any way can we let the sensor detect the range of the vehicle for a certain period and calculate the speed accordingly?

I really don't think an ultrasonic sensor is the right device.
If a vehicle is approaching at more than 10kmh-1, you really need more range than ultrasound can provide, to give a warning much sooner than 2.5 seconds.

Maybe Doppler radar?

Basically the cane wont be detecting fast moving vehicle from far as the user can hear about. The purpose of the sensor near the tip is to give the user confirmation of the moving vehicles has stopped. Any idea how to program it? Let's say record distance every few millisecond and calculate the acceleration?

Let's say record distance every few millisecond

Speed of sound is around 340 ms-1.
How many pings at maximum range can you do in "a few milliseconds"?
Do the arithmetic.