Consider the following two sentences:
Council is to visit this place in the next year.
Council is visiting this place in the next year.
Any of them denotes an action, which is planned. What is point of difference between them?
Both are okay. Both show that the action is planned and likely to happen.
The be to + infinitive structure is generally used to discuss formal or official arrangements or to give formal instructions or orders. The BBC describes it further that --it is also frequently used in newspaper, radio and television reports to refer to future events. It expresses near certainty that what is forecast will happen.
On the other hand, the present continuous is also used when the things are pretty sure to happen.
"S is to V" has several uses:
It's actually the first construction that expresses less certainty than the first. It is the appropriate one to use when reporting other people's plans/predictions, without making a subjective commitment about whether you believe that plan/prediction is likely to come true.
It is for this reason that a journalist is more likely to say "The government is to start building the subway next year" than "The government will start building the subway next year" if there is any doubt about whether the building will occur.