You can drive round the city, if you like sitting in traffic jams, and paying lots for the privilege. If you commute between S. Gloucester and the city centre, you are paying 40 pounds a month or more in fuel alone. Leave the car at home for a month, and that is now saved money.
You could get a bus, but if you have to rely on FirstBus for your bus service, well, you are paying enough to afford a new bicycle ever year.
You can walk, if you live close to where you are going. But it is slow -because you are going at walking pace. On a bike, you can nip out to the shops, buy fresh bread for breakfast and be home almost before the kettle's finished boiling.
You could get a train -these are fast and can have predictable journey times. Funnily enough, bike and train go together very well for longer distances, but in Bristol, there isn't enough of a suburban train system for it to be that useful. Some people do mix train and bike for their commutes, and very happy they are too.
If you commute by car, that thirty to sixty minutes of every day spent sitting in a traffic jam, or sitting at the lights staring at the cars from the other half of the junction that are now blocking the no-blocking part of the junction you cannot enter yourself is a waste of time and money. And it is not exercise, so you need to find a different time of day to get fit, or get used to being unfit and unhealthy. Once you get to work -or to be precise, get near work, you have to start circling round the "secret" roads you've learned about, where there may just be somewhere to park if you are patient enough. Then there is the ten to fifteen minute walk from the parking space to your place at work. And if that secret parking space you have found is not quite legal -it's blocking a dropped kerb, partially blocking a driveway, on a wide piece of pavement- you are left wondering if today you get a ticket -or worse, a towing.
If you have to do the school-run, you are not merely driving your children round the city, getting them used to sitting in traffic jams as a start to the day, you are doing at what is the worst possible time to drive across Bristol. Because every other parent driving their kids to school is also trying to cross the city to arrive slightly before the school day starts, usually 8:45 or 9 am. When you get to the school, you are left trying to find somewhere to park that hasn't been occupied by other parents, then rush the kids in to the playground, casting an eye back to see if today is the one day per term when the traffic wardens issue tickets outside the school. Then it is out of the playground, and into the commute to work. As this is at exactly the same time as every other parent driver in the city is trying to get home or to work, the traffic jam you are now in is even worse than the one to school