Yes. And when a program's benefits outweigh its costs, it seems weird to say that the program is a damper on economic activity.
In other words, if Option A is "get zero dollars", and Option B is "spend $1 to get $2", it is unfair to complain about B's "cost" (spending $1) in isolation.
Yes, taxes to pay for roads do indeed discourage economic activity.
This is a cost.
And the benefit that we get is the roads.
And in this case the benefits outweigh the costs.
But just because the benefits outweigh the cost doesn't mean that the cost doesn't exist.