However Istanbul is geting ready for a big change to overcome this poularity. Last two years the city is re-urbanising its major areas. Many old neighbourhoods are being almost rebuilt or rennovated. Not only that but the new residential areas are being built around the city in the late five years and still continiuing.
This brings in a crowd of peaple with a lot of construction in and around the city. Jst because of this reason the lenght of the rush hour has expanded and the public transportation became over populated during these hours.
It is important to appriciate the public transportation in the city. Personally, I like to move and not to get stuck in traffic for longer hours (which sometimes you can not run away from it!), like many Istanbulians. If I am driving, I always look for alternative roads that is fastmoving. On my smart phone I have two apps to help me for this:
1-The municipality official traffic app IBB TRAFIK.
2- Yandex Maps app that shows traffic in Istanbul. Unfortunately Google Maps do not have that function here in Turkey. Yandex also will give you street view of the major areas in the city, which I find it very helpful. Even many real estate agents are using this app. (Both in itunes and google play)
So these are handy if you are on the road, but always get some time to strech your legs and walk because you will need to many times. Istanbul is not a flat and elevated city, especially during these days when we have many ongoing constructions in the city. However walk... it will save you more time rather than taking a taxi or public transportation.
If you are going to cross the Bosphorus to other continent, the best way is using the Public Ferries . Hop on a ferry and enjoy the quiet ride across Bosphorus. Don't forget to buy a Simit (a kind of bagel with sesame seeds around) to feed the seagulls :)
Other public transportation options are busses, subway, finicular and tram that runs until late midnight arond the city. You can buy a public transportation card from many vendors at the stops and use it to load credits that you can use on every Public Transportation including ferries. The widely used option for travellers is just to use the machines to get tokens for each ride.
One new addition by the municipality is the bicycles that you can rent. Very cool looking bikes but no gears on them makes it difficult for uphills. Also difficult to find the paces to get them around the city (there is one in Sultanahmet Sq. but still check updated map on the link above). 2 TL per hour, but you need credit card to get the bikes.
Be wise and Enjoy your time..