Looking at the map, Dholera looks like a small town almost equidistant from Bhavnagar, Baroda and Ahmedabad. What's the rationale behind placing an international airport there?
Your question has most of your answer. I will take liberty to supplement a few more cities: Anand/Nadiad (~70 km), Rajkot (~200 km) and if you start a water taxi, Surat downtown around 1 hr away.
Ahmedabad is close to saturation. With the advent of ME3, lot of traffic from the surrounding area's drive to AMD. Dholera is singularly at the center of most of Gujarat population centers.
In addition, Dholera SIR is in development. One should view this as something as ambitious Singapore & development of Changi. Only the question of execution now.
Well, going by that logic, we need just one airport per state, at the central/equidistant point from all population centres. Unfortunately, things don't work like that in the real world. When you say Ahmedabad is approaching saturation, I assume you mean the terminal? There's no way Ahmedabad is getting saturated in terms of aircraft movements, even accounting for general aviation. I'm happy to be corrected on this, but it seems counterproductive to build an airport equally inconvenient for everyone instead of improving capacity at Baroda, Surat, Bhavnagar etc. For the record, I don't buy the "as ambitious as Singapore/Changi" argument, because I'd rather wait for the promises to the SIR to start bearing fruit than put the cart before the horse on the basis of some politicians' promises.
Actually, Gujarati's are provided options by the neta's and babu's offer that always seem to range in degree of inconvenience. Afterall, all them have an agenda to overstaff the agencies, airlines and so forth with people from their own states.
AMD is growing at roughly 20-25% in the last 5 yrs or so. If anything, it is growing faster than the overall growth. If there has been a 'dip' in traffic, it has been due to the construction on the runway. If you look at capital projects, you need to forecast for next 5, 10, 30 yrs and so forth. If it is not saturated today, it will be in next 5 yrs. There are additional 7-8 active airports, viz. Vadodara, Rajkot, Bhavanagar, Diu, Porbandar, Surat and so forth. In addition, neither Anand/Nadiad have airports.
There is no way all of these cities can support expansion or proper growth. One way to resolve this is to pool the resource and create a central location. My understanding that MEGA will be extended to Dholera. In addition, the HSR can be extended to Dholera and perhaps Rajkot. This would create a catchment area ranging from Bharuch to Rajkot. As I mentioned, Surat can be connected with a ferry for a v. short ride. A bigger metro area than Mumbai or Delhi.