Again, any incentives that can be put in place to upgrade technology, whether it's in aircraft or in trains, or to upgrade the fluidity of the system have a very positive environmental impact because the more efficient the system is, the more smoothly it operates; without bottlenecks and a lot of downtime and stop-start activity in the system, the more environmentally friendly it is per unit of GDP. I think investing in a really good, highly efficient system using the latest technology is probably the way to go.
On September 22nd, 2016. See this statement in context.