The first 50% of the road is completed in $250,000. After the rest is completed the total amount used is $550,000. This means the second half required 550,000 - 250,000 = $300,000.

The extra amount required for the second half was 300,000 - 250,000 = 50,000.

Or in terms of a percentage of the amount required for the first half is ir 50,000/250,000* 100 = 20%

**The second half of the road cost 20% more to construct that the first half.**

The total cost is 550,000

The cost of the first 50% = 250,000

Then the cost of the second 50% = 550,000 - 250,000 = 300,000

Now we need to calculate the difference between both halves.

==> The second half costs 50,000 more than the first half.

Now we need to calculate the percent of the extra cost.

==> 50,000 / 250,000 = 0.2

==> 0.2 * 100 % = 20%

**Then the second half costs 20% more than the first half of the project.**