A cargo trike replaces a second car for households whose second car does short local trips with awkward loads. It does not replace one that does a highway commute, and we will say so before you spend the money.
Work backwards from the trips. If four of your five weekly second-car journeys are under four miles with kids or shopping aboard, a trike covers them, and the fifth is a taxi fare. If two of them are 30 miles on a highway, it does not.
The two things people underestimate are storage and weather. A trike needs somewhere secure and roughly the footprint of a motorcycle plus a bit. And you will ride in rain — a good jacket is not optional equipment, it is part of the purchase.
