Final answer:
The sentence with improved structure is: "To save time and gas, a person can plan errands to make one car trip rather than making several trips."
Step-by-step explanation:
The sentence with improved structure is: "To save time and gas, a person can plan errands to make one car trip rather than making several trips." This revised sentence removes the awkwardness in the original structure by simplifying and clarifying the sequence of actions. The use of "making" after "than" aligns with the parallel structure of the sentence, making it grammatically correct and more straightforward. It conveys the idea that planning errands efficiently allows a person to consolidate multiple tasks into a single car trip, saving both time and gas.