The use of congestion charges accomplishes two things. Firstly, it's intended to be a deterrent for individuals who commute or drive in and out of town on a regular basis. By preventing too many motorists in the zones at once, pollution is lessened and traffic is less. This naturally leads to more car pooling as most people don't want to pay the excessive charges on a daily basis themselves, but they don't mind sharing them with others in a car pool, or using public transport. Either way, mission accomplished!
Other people have instead purchased hybrid vehicles because the congestion zones are accessible without the charges for people using vehicles that meet the appropriate guidelines. Again, mission accomplished with regard to air quality.
For those motorists undeterred by the congestion charges, the monies collected are used to help with the required improvements for the transportation and roadway systems. Ultimately, this may help free up more territory for more motorists, which could help remove some of the need for charges, or at least lower the fees.
Though initially despised by many motorists, the congestion zones have led to benefits for many motorists as well. The motivation to move to a hybrid car has led to better fuel efficiency for some. For others, car pooling has helped save on fuel costs. Couples that drive together may have to share the charges, but there are potentially car insurance discounts available for combining your car insurance policies or only using one car.
Even if you're one of the people who doesn't appreciate the congestion charges, you could use the opportunity to respond by getting into a car pool, looking at alternatives such a bicycle or public transport, or buying a hybrid car. You might also rethink your car insurance set up.
Bear in mind the following points about the congestion zones: