Crazy Taxi has a ranking system that scores you on how much money you gather in your run.

Money is won by taking people where they want to go. The fares are color-coded.

• Red fares usually are the closest, but give you the least amount of money.
  
  
• Orange fares are usually further than Reds, but give a little more money.
  
  
• Yellow fares again is even farther away, and gives more money.
  
  
• Light Green have a very good pay out.
  
  
• Green are the farthest, but they give the most money out of all.

Money can also be gained by performing Crazy Combos while you have your fare. For example, if you pick up a green fare and perform many combos along the way to your destination, you will rake in the cash.

It is also very important to get there as quickly as possible, as this also affects wether you recieve a time bonus on completion of the fare or not.

• Bad = Customer will usually jump out of the car.
  
  
• Slow = The person will not be very pleased at your insane taxi driving antics.
  
  
• Normal = +2 second time bonus
  
  
• Speedy = +5 second time bonus

There are many schools of thought on how to get the best fairs. Some people say to stick to nothing but reds and get as many customers as possible, while others go for a mix.

We tend to agree with the mix strategy. Red fares can be very useful to extend your time when you are getting low. Speedy drops will net you five extra seconds and Red fares are usually very close to their spots making Speedy a very easy score to get.

Oranges and Yellows are more than acceptable when there aren't any Greens in the immediate area. Not only that, but they can frequently net some awesome cash. When you do get a Green, piling on the combos can really pump up the fare.

License Rankings are what you are shown at the end of runs as your end-game results, or how well you did being a psycho 'Taxi Driver'

• No Money = No License
  
  
• $.01 - $999.99 = E License
  
  
• $1,000.00 - $1,999.99 = D License
  
  
• $2,000.00 - $2,999.99 = C License
  
  
• $3,000.00 - $3,999.99 = B License
  
  
• $4,000.00 - $4,999.99 = A License
  
  
• $5,000.00 - $9,999.99 = S License
  
  
• $10,000.00 - $19,999.99 = AWESOME! License
  
  
• $20,000.00 or more = CRAZY TAXI! License

This information was credit to an ign guide uploaded in 2000, but I thought it would be better placed here for any people on steam wondering how the ranking systems worked (like myself)

The guide in question (their's has more color!).