I support charging people who decided to drive in but think the pay-once-and-drive-all-day approach encourages exactly the wrong sort of driving.
I'm also amused that Heidi Alexander's go-to example of what should be easy and free is a one mile car journey, when she spends the rest of her time encouraging people to do those journeys by bike or on foot.
Flexible, distance-based road user charging is now increasingly feasible (I assume that the technology for this exists by now, but again I haven't been following this lately)
Technologically it's straightforward, but there's rather too much glossing over the practicalities and legalities. Will you need a tracker, or an app, and what happens if you have neither? Do the legal powers to make it happen exist, or does it need an act of parliament?