5. (20 points) On a grid, there are three locations $A, B, C$, with each small square having a side length of 100 meters. If roads are to be built along the grid lines to connect the three locations, what is the shortest total road length in meters?
【Analysis】Since it is necessary to build roads along the grid lines to connect three locations, we can first find the intersection point $D$, and then add up the lengths of each segment respectively.

【Solution】Solution: As shown in the figure,
we can get $100 \times 4 + 100 \times 3 + 100 \times 2 + 100 = 1000$ (meters).
Answer: The shortest total road length to be constructed is 1000 meters.