Answer –  44 Steps

5 steps forward 3 steps backward
2m 8 steps
similarly,
4 m 16 steps
6m 24 steps
8m 32 steps
10m 40 steps.
now in 4 steps he will fall in hole.
Hole is after 13 m not at 13 m .

After his13m there is a big hole in the road.
There is a hole after 13 m….but exactly we don’t know how far the hole is  from the man. So we can’t say exactly where the man is going to feel the gravity!!!
BUT!!!!!!
If this means the hole is 13 m away from the hole answer is 5..
BUT!!!!!
If it means the hole is just after 13 m then another extra move will be needed! So the answer will be 6…

For….5 move strategy….

Explanation:
1st step: He goes 5 ft and return 3 ft. So he visited all distance between 1 and 5 ft.His current position is 5-3=2 ft from initial!
2nd step: He goes 5 ft and return 3 ft. So he visited all distance between 2 and 7 ft.His current position is 7-3=4 ft from initial!
3rd step: He goes 5 ft and return 3 ft. So he visited all distance between 4 and 9 ft.His current position is 9-3=6 ft from initial!
4th step: He goes 5 ft and return 3 ft. So he visited all distance between 6 and 11 ft.His current position is 11-3=8 ft from initial!
5th step: He goes 5 ft and return 3 ft. So he visited all distance between 8 and 13 ft.
And in this step he’ll feel gravity!!!

For six move strategy:
Explanation:

First five moves will be same as before!

6th step:His current position is (13-2)=11 He tries to go 5 ft again. But in the mean time he will fall into the hole…if the hole is situated just after the 13 m….exactly on 14 m distance