The final rules were published on Friday by the FIA. Among the most significant changes there will be a restart grid of the races neutralized by the safety car, the parc fermé after the third free practice and four engines per season. 

The new FIA regulations for 2015 Formula 1 continues the open way for efficiency, lower budgets and the desperate attempt to make the races more exciting. The most controversial and significant change corresponds to the neutralization of the rules of racing for the safety car.
If the safety car comes on track after the first two rounds of the start or neutralization and before the last five laps of the race the procedure will change. When the track is ready to restart the race the safety car will head to the pit lane and the cars must stop at grid in the sort order to start a new race as the start of each race.
Drivers like Nico Rosberg and Daniel Ricciardo have already expressed their disappointment with this new rule, believing that it can make a big disadvantage for the drivers at the top and is not a fair idea because of the difficulty of making a good start. There are other opinions as those of Fernando Alonso and Lewis Hamilton, who are skeptical. For the Spaniard is no difference between both ways and there is no reason to complain. Stop starts are widespread in karting.
There will also be changes in the use of the power units. These will be limited to four per season – except if there are more than twenty tests, which will be five – and the penalty for change, rather than starting the race from the pit lane they will be starting it from the back of the grid. From 2015 the parc fermé shall apply from the third practice session instead of qualifying, as was done recently. Still, working hours on Friday will increase to eight.
To reduce costs the possibilities of aerodynamic testing are reduced and pre-season testing will take place in Europe. It is noted that only two tests will exist in 2016.
As for technical regulations the heating blankets will be kept and changing tyres is expected in the future. The regulations will change in order to make the front even safer and aesthetic, as promised the organization after seeing the results. For safety rack systems are mandatory and regulations on the brakes will be more stringent.
The expectation is in the restarts of the races and it of course generates controversy these days.