For #2, running off the walkway gives a greater boost to speed percentage-wise; since travel time is inversely proportional to speed, it is thus reduced greater

For #2, running off the walkway gives a greater boost to speed percentage-wise; since travel time is inversely proportional to speed, it is thus reduced greater. (For positive u and v`>v>1, v`/v<(v`+u)/(v+u))