You can also check out theses annuals for ideas
Unfortunately they are from 3 different annuals, but all the annuals are a great source of symbols / styles / fills etc
I agree with you, creating all the streets by hand is no easy task. It's one of the main reasons why I scrap every city I attempt! It always ends up looking unnatural and forced for me. But some of the designers here create masterpieces, so I know it can be done.
Yes, I'm colorblind. But my pink fields and orange forests are avant garde!!
Both programs can do the job. You could even use PS/GIMP or Illustrator/Inkscape. You should be more precise concerning the style you imagine for your maps: top down view/3D, realistic/atlas style etc.
AFAIK there is no ready to use style for what you want. That means you will have to spend time on learning the desired program and then work on the style.
You may want to try out the RPG Citymap Generator (you can find it here: http://www.stargazersworld.com/2009/...map-generator/) to get a starting point for street layout; it has presets for modern cities in addition to more medieval/fantasy stuff.