

For anyone else who’s never heard of hydrogen reduced steel before, here’s the gist as far as I could understand from a quick web search:
Raw iron ore is usually mined as iron oxide. To make that into metallic iron, you need a way split up the iron oxide molecules and carry the oxygen atoms away. This is traditionally done in a blast furnace using coal. In addition to being burned as fuel, the coal also provides carbon atoms, which will rip the oxygen off the iron and use it to form carbon dioxide instead.
The hydrogen reduction process proposes to substitute hydrogen for carbon. This changes the byproduct from carbon dioxide to dihydrogen monoxide, AKA water.
Alright, I’ll take the bait. Let’s do some recreational math
This web page contains average passenger car fuel efficiency broken down by year. The most recent year available is 2016, so we’ll use that: 9.4 km/L or 22.1 miles per gallon. A gallon of gas has about 120MJ of energy in it. So, an average car requires about 120,000,000 / (1/22.1) = 5.4MJ per mile
This web page has calories burned for different types of exercise. I separately searched and found that the average adult in the US weighs around 200LBS, so we’ll use the 205LBS data, and I’m going to assume that “cycling - 10-11.9 MPH” is representative of the average commuter who isn’t in too much of a hurry. That gives us 558 calories per hour, or 55.8 calories per mile (using the low end of the 10 to 11.9mph range). That’s equal to about 0.23MJ per mile (as an aside, it’s important to note that the calories commonly used when talking about diet and exercise, are actual kilocalories equal to 1000 of the SI calories you learned about in school.)
Moral of the story: an average bike ride consumes around 20x less energy than an average drive of the same distance.