The Speed Problem:
I noticed that when the car enters a cave my speed per hour gets reset back to 0 and when I leave the cave it goes back.

Plus - The Map Display Problem:
When I get inside the cave the map display feature of the car/arrow icon stops working:
(the car/arrow icon would stop moving and then jump back to the end of the cave when I leave).

I believe that the map feature and speed is working by gps to locate the vehicle location and time to calculate the speed which makes the car km/h / m/h to be not accurate:
Meaning that when I enter a blind spot from gps, the car location won't be changed and the map display of the car would just stay put ,
Plus - When the car location is not changing then the cars speed would be set to 0 by the calculation cause it's using only the location change over time.

My solution to this problem is to make an option which you can take the speed from the car itself without having the trouble of calculating it yourself. -

Most people of this time have already made the switch to electric vehicles which have the base "computer" inside of them which shows the driver their speed and allows them to download certain apps to their vehicle such as Spotify and Itunes.
Plus - For some of those vehicles the Waze app could be added.
Meaning that the Waze app would be able to request from the car the ability to track its speed.

With this solution we can find out exactly at what speed the car is driving at all times without worrying about calculations.

With this information we can also know roughly the exact location of the car.
How do we do it?
Simple. We just take the speed of the car and multiply it with the time that has passed.
For example:
Speed = 90km/h
We would place a constant variable for the Time to be 1 Second that would not change ( it would mean that the map display would change every 1 second)
Then:
We calculate it by this equation:
Distance = Speed in km/h * Time in hours

For our example:
First we need to change it from km/h to m/h:
90 / 3.6 = 25 m/s
Then Distance = Speed * Time:
Distance = 25m/s * 1s
Distance = 25 meters

After that we can know the distance the car traveled the past second, and we can add it to the map along the road.
And I know what you all think.
WHAT IF the Car driver choose to reverse or change a path in the middle of the road.
And that's why this function would ONLY work where there is no connection to GPS, and then when we get back connection to GPS the car would jump back to the location from the GPS.

There for we can now know the exact location of the car on the road, Plus - we can know its speed at any given time(NOTE: This feature could replace the current way of speed tracking on any road).

Another Solution IF we can't use the vehicle speed:
We can also use the vehicle speed for the past 5 seconds before going into the blind spot + use other cars past records speeds of driving in that road and the speed numbers of vehicle users there are on the same road at the moment, and get the average speed of all of them.
The way we can know the speed of vehicle users who drove this road in the past?:
Simple,
we just do the exact same equation from before just placing the time as the time they spent on the road and the distance of the road.

And then we know the speed and we can find the location of the vehicle on the map just like we did before.

That's my solution I hope you liked my detailed explanation and give me a feedback!
If you have any questions let me know on my work Email: Astrom.Chiprut@gmail.com