Sacn a roadway 15-20 seconds which is equivalent to the distance of half of a block?

false

Explanation:

we know that when we drive on urban area on road we can scan roadway 10 to 15 seconds ahead that is equivalent of 1 city block as

that if we travelling at 60 mph we look 12 to 15 seconds = about two or three block

but we should looking about 15 to 20 second ahead of your vehicle for safety

it is depend on speed also because in some cities standard block are as wide as 660 feet