Some types of lava flows faster than others because of factors affecting it
its magmas temp
chem composition
and amnt of gas it contains
if it has high temp low silica content and more amnt of gases it is less viscous which is easy to flow
7 3 7
Molten rock is much thicker than a liquid like water. Even lava flows with the least viscosity (the least thick), will only flow at a maximum speed of a few kilometers per hour