By taxi
Mumbai's taxis are allowed into Navi Mumbai. Hired cars are also a good way of getting into the city. If you are travelling from Mumbai to Navi Mumbai most taxis will expect the passengers to pay the toll on the bridges connecting the cities, in addition to the metered fare.
Here is an advice - Most taxi/rickshaw meters are doctored, at least in Navi Mumbai. So, better go by branded cab services - Mega Cab 022-42424242, Meru Cab 022-44224422, Gold Cab etc. You would get them at 30-60 minutes notice, they are sparkling clean, air-conditioned, punctual, honest, GPS-equipped-monitored and thus far secure at anytime. You get an SMS saying driver name, mobile number and car number 30 min before scheduled departure. 03-box cars only - Indigo Marina and Maruti Esteem only. Call center 24 hours, and not much difference in the day or night charges. Charge Rs.15 per km point-to-point, with just Rs.2 extra for first km in the night time. Infact, domestic airport has a dedicated areas in the common taxi stand for Mega and Meru cabs. e.g. You would shell out Rs.450-600 from airport to navi mumbai depending upon where you go, whereas other cabs may fleece you to the tune of 1000-1600 easily while giving poor service.
By bus
Mumbai's BEST and Kalyan - Dombivli's KDMT bus services run a few buses into the city. BEST bus numbers in the 500 series are the ones to look for.Navi Mumbai Municipal Transport NMMT bus services run buses inside Navi Mumbai.NMMT has extended A/C bus service to Bandra & Borivali and is a very convenient way to travel to Mumbai as it has pressed latest Volvo buses in service. BEST has also started its A/C king Long buses from Navi Mumbai to Mumbai but the fares are higher and buses are not as comfortable as NMMT Volvo buses.
By plane
The city does not have an airport yet, though that will change in a few years when the new international airport to serve Mumbai will be built in Navi Mumbai. Work on City & Industrial Development Corporation of Maharashtra's airport project in Navi Mumbai has already started as of June 2008, after some issues relating to land acquisition are sorted out and clearance of the Union Cabinet is obtained. The closest airport is in Mumbai. Once you get off, you can take a train, bus or cab to get here.
By Auto-Rickshaw
Mumbai's auto-rickshaws are not allowed into Navi Mumbai. However, you can catch one right up to the toll gate at Airoli, walk across and catch one on the Navi Mumbai side. Similarly you can catch one to Mankhurd and then change over to a taxi to get to Vashi.But sometime if you are lucky , you can get auto rickshaw to makhurd from vashi also to vashi from mankhurd.Since these auto rickshaw come to mankhurd for gas filling since there are still less number of GAS stations in Vashi.
By train
There are two train lines running through the city. These suburban railway stations are quite neater than those in mainland Mumbai. Navi Mumbai's railway stations are one of the very few stations in India which boast of beautiful infrastructure. The trains really are the best transportation option for Navi Mumbai, considering the region's high traffic and pollution.
Mumbai's Harbour Line has been extended to serve Navi Mumbai. The most important station is Vashi, but there are many stations within the city, including Sanpada, Juinagar, Nerul, Seawood, CBD Belapur, Kharghar, Mansarovar, Khandeshwar & Panvel. The Panvel station is last station on Harbour line.
There are two rail line that connects Thane Rly Stn from Vashi and Panvel. Service on this line has improved a lot now because of more trains added.
There are 5 suburban trains daily between CBD Belapur and Andheri 2 in the morning and 3 in the evening
With respect to January 2011, the Central railway have also started 12 car coaches between Thane-Panvel, Thane-Vashi lines. There are also fast trains running on this route.
Panvel-CST bound trains are soon be increased in carrying capacity from 9 to 12 coaches. This will ease the rush in the wee hours of the day in this line.
By car
Navi Mumbai is well connected with Mumbai. There are two entry points from Mumbai, via Chembur/Mankhurd and via the Airoli exit on the Eastern Express Highway. It will cost you Rs. 30 in toll. From Thane, you can enter the city via the Thane-Belapur road, and in fact the Airoli exit joins the Thane-Belapur road. This road has numerous entry points into the city, so you need to confirm which one to take.
The Thane-Belapur road also links up to the Mumbai-Pune expressway.