Is there a possibility to calculate the velocity of a car if I just have the GPS data and my acceleration?

Question

I already tried the integration of acceleration, but the values I got where not realistic.

for that I used https://de.mathworks.com/help/matlab/ref/cumtrapz.html

vx.data = cumtrapz(ax.data);    %integration of acceleration
vy.data = cumtrapz(ay.data);           
vz.data = cumtrapz(az.data);           
vx.time = ax.time;
vy.time = ay.time;
vz.time = az.time;

Is there any other posibility? Maybe with the GPS data?

Thanks!