In the United States, positive train control was required by Congress, so a number of railways on a number of lines in the United States are moving towards that. I understand it's quite a challenge in terms of technology and in terms of money.
When we came to look at the situation in Canada following the Burlington accident, we decided there are a number of systems out there and we're not going to be prescriptive and say that it has to be PTC. We've outlined the safety problem and said there could be a number of ways whereby you get to that result, that you fix that safety problem.
This is a matter that I believe has been sent to an advisory committee and we're hoping there will be some positive movement on it.