—so you do keep that in mind as you're figuring out what the quantification is.
Mr. Chair, the important part with this as well is to make sure you balance it against the reasonableness of that happening again. Everything we've done since July 2013 is to prevent that from happening: preventing derailments from happening, and mitigating, should a derailment happen, to ensure the cleanup can be done quickly, with the third principle being that the polluter pays. That's been the focus for us since then.
This is part of it. Part of it is the lowering of the speed in urban areas, as we talked about. Part of it, too, is developing the new tank car standard. Part of it is saying that you have to phase out the older legacy DOT-111s, which we've done as well, and creating a schedule upon which everything has to be converted to the brand new car that's coming out soon.
It's a work in progress. We'll continue to work on it. We continue to monitor. You had CN officials appear before you as witnesses. They gave good information. They have a responsibility for safe operation as well. It's not just about what we do here in creating laws. They have to operate safely on a day-to-day basis, and they need to invest in their infrastructure, and we'll be here to hold them accountable.