You can't keep such huge projects secret. Some clown will spill the beans sooner than later. After all, there would be hundreds of people involved in such projects. The only way out is to have a deception strategy by making a two or more stretches many miles apart so multiple options are available.
Read, read and read again. For Chrissake,
it is the first such IN INDIA!!! It's never been done, tried and tested in India before!
Nations known to utilize the strategy of highways constructed to double as auxiliary airbases in the event of war are Singapore, Sweden, Finland, Germany, Poland, Taiwan, and Russia.
Have I helped you as was your wish?