There are other obstacles to the LaGuardia Air Train besides Governor Andrew Cuomo's recently authorization to use eminent domain for the project.
The LIRR will be unable to run trains at the same level of frequency as the Airtrain. Passengers could end up waiting ten to twenty minutes for the LIRR.
Completion of Communication-Based Train Control on the 7 line will only increase capacity from 30 to 32 trains per hour.
Travelers with luggage and children will face challenges attempting to board and exit already packed rush hour subway and LIRR trains.
Governor Cuomo apparently never considered how this issue will be resolved when contemplating this project. In 2014, Cuomo promised that the LaGuardia Airtrain would be running by 2019. Now he has said 2022.
Both this date and a 26-minute trip to Manhattan appear unrealistic.