Your car consumes more fuel in traffic jams or when you use it frequently for short journeys.
When traffic is dense, you brake and accelerate more frequently. This jerky driving style pushes up fuel consumption unnecessarily.
Plan and combine your journeys to make them cost-effective. Wherever possible, avoid rush hours and traffic jams. Optimise your route so that you can drive smoothly, limit acceleration and braking and reduce mileage.
If you get stuck in a traffic jam, turn your engine off temporarily when safe to do so. This always saves energy.