WWE made the concious decision back in 2014 to drop February's Elimination Chamber pay-per-view this year and instead create a new event called Fast Lane for the first time.
The reports at the time suggested that The Elimination Chamber would instead be used in the build up to Summerslam and looked like a creative way to build the ratings after Wrestlemania season.
This made sense, the fact that there were no longer two titles at last year's Elimination Chamber meant that there was no need for the two chambers and it seemed like there wasn't enough build up from the Royal Rumble to follow through into the February pay-per-view.
Stephanie McMahon appeared on The Wrestling Compadres Slamcast this week and informed the WWE Universe that the decision was made because most of the venues that the WWE use now have large score boards above where the ring would be placed and this made it hard to hang the ten tonne structure.
Some buildings were creating some problems and officials would have had to check the Chamber could be hung before the venue was booked. Fast Lane is a much more straight forward event without a gimmick match as the main event.
WWE went through a phase where a lot of their pay-per-views were named after gimmick matches, TLC, Hell in a Cell, Elimination Chamber, Extreme Rules and Night of Champions when this really isn't needed any longer and they can now focus more on the build up of story lines rather than putting superstars in matches because they are a part of the event.
Fast Lane will allow apt build up before Wrestlemania which is just a month after the February show, this will also allow Brock Lesnar to miss the event if he is still WWE World Heavyweight Champion because there wont be a need for a world title match without the Elimination Chamber structure.
The Elimination Chamber is still very much a part of WWE's calendar, it will just be moved to later in the year and the Inaugural Fast Lane will take it's place.