[S2 Maths/Science and up: Resistance]
When we see a short road, we expect to reach our destination faster than the long roads. So we assume; but in reality, you're not the only one on the road. There are other drivers that help to comprise the expansive network of transportation we call 'traffic'.
It's never easy to discern if things will simplify, or improve simply by build roads straighter and shorter. This is an interesting paradox for you to think about: How should Singapore's roads be organised or arranged to capitalise on this paradox? Do drivers want shorter roads, or shorter travel time?
It's not an easy answer. A shorter road would make us think and feel that the fuel consumed is less, since the travel distance is less; but in reality, being stuck in a high-traffic short road can cost a lot more fuel than being on a wide road where you don't have to start & stop, and start & stop, and start & stop your wheels over and over again, which is arguably the most energy-consuming part of travel.
Questions like these aren't always clean & clear, like the questions you tackle at school. PSLE exam questions tend to test lateral thinking a lot more than your usual homework; stay on your toes, and watch out for counter-intuitive questions!