Exodus 12:37
And the children of Israel journeyed from Rameses to Succoth, about six hundred thousand on foot that were men, beside children.

If there were 600,000 men, then there must have been a total of a few million people that took part in the Exodus.

Assuming there were 2.5 million poeple marching 10 abreast, with a space of 1 meter between the rows, the line would have been 250 kilometers long and would have required five days (assuming 5 km/hr 10 hrs/day) to pass by any fixed point.