Transport is a serious issue in Bristol. It is easy to look at other cities and be envious of aspects of their transport systems. But the grass is always greener and a regular tube rider in London will tell you it is not the favourite part of his day.
A common line of thinking is "buses are rubbish, I have no alternatives, I must drive." But solutions lie not in absolutes but in small changes and a mixture of alternatives that are right in the different situations.

Road space required for 60 cars
If and when Bristol gets a rapid transit system, it will largely follow existing bus routes and will replace some of the more frequent and regular bus services. It will be an improvement certainly, but it will not instantly solve local transport problems. In fact it may only delay the progression of an ever worsening situation.
The other problem with large infrastructure changes is that they take lots of money and time to bring into service, cause controversy and they disrupt the existing network while they are being constructed.

Road space required by 60 bikes
Ultimately, transport problems are going to be solved more by the decisions we make as individuals and not by the government or grand transport schemes.
Everyone is part of the problem and everyone can be part of the solution.
Cars will always be one of the transport options open to people, but owning and using a car does not stop one from using alternatives some of the time. Every journey not made by car helps.

Road space required by 60 bus passengers
All of the above could save you money, even the buses, especially if you reached a point where you could give up a car entirely. If that is a bridge too far you may consider sharing a car with a neighbour and splitting the operating costs.
If you work out what you are saving, it can become much easier to justify hiring a car when you do have a road trip or need to transport stuff around. You might also find getting a taxi more often is a nice treat you can afford because of your other savings.
Talking of taxis, there are a number of schemes (see BBC article and Texxi) going on around the UK where people are sharing taxis. This is good all round because it reduces traffic, and waiting times at taxi ranks, reduces the trip cost for passengers and even nets the driver more money (because the share schemes usually work on a flat per head rate which is lower than a normal taxi fare but because there are multiple passengers adds up to more than a basic fare for the driver).
Fundamentally, people travelling alone in their own metal boxes just takes up too much room on the road (as the pictures in this article illustrate). The only way we will solve transport problems is by not getting into metal boxes (walking or cycling) or by sharing metal boxes with other people. Driving a car is far less detrimental when there is more than one person in the car.
As a society we are less and less willing to mingle with other people and strangers, but we need to overcome this if we are ever going to improve traffic conditions. Using cars less often is part of the solution, sharing cars more often with more people is the other part of the solution. It is all in the balance that we strike, but fortunately we do not have to wait, we can do this right now.
The pictures in this article come from the city of Münster in German