None of us can tell you whether this is "normal" or not, signals and connection speed differs all the time between operator and location. Especially when on transport driving, objects around you could potentially interfere with the connection and as you move further away or towards the source of the connection, the signal strength will decrease/increase which affects speed.
For me, it's normal sometimes, but it depends on travel route. Sometimes it will work fine, other times it won't work as well. However my connection speed will be the same throughout all usage attempts, not for specific purposes better than another.
On that note, make sure your phone supports 4G otherwise you'll be forced onto 2G/3G.
Consult with your operator for further inquiries on your phone deal package if I were you, they will know more details than us about your phone package.
