Sure. Thank you for the question.
As you mentioned, there is a $4,000 cap in the existing deduction. There is also a restriction that effectively says you can't deduct more than half of the income you earned from the job. The idea there is essentially that we recognize that people travel for a variety of reasons all the time, and I think we would all think it reasonable that people who are choosing to incur expenses to earn income aren't going to travel just to earn income if they're going to spend more on the travel and the expenses to get there. This provides a simple catch to make sure that the income this person would earn from the travel would actually be significant relative to the expenses they incurred.
There's also a restriction in the existing deduction that limits it to a minimum travel of 36 hours, which speaks to what we heard from stakeholders in terms of being able to move for temporary jobs and projects away from where they normally live as opposed to just ordinary commuting. All employees may have commuting expenses and some people may live far from where they work, but those aren't typically deductable by most taxpayers and that's not really the gap that this provision was meant to address.
Finally, I would flag that there's a provision that says the deduction is available for travel to a work site in a city where the individual isn't normally working. Again, this was getting at the sense that this is about travelling away for temporary jobs, and it's not about commuting to your day-to-day job that you normally work at. That latter provision was modelled after an existing rule in the tax recognition for the U.S.