Take one Freightliner off the line, then that will not be one extra lorry, you will be looking at something like 40+ lorries (round trip of train) all artics too ! (of course 2 freights...close to 80 to 90 more lorries....)
Of course a freight train would remove much more than
one lorry off the road, but then I’d hope that any passenger train
worth running would remove more than a dozen cars off the road too – I’m just trying to use a simple example to show the kind of ratio where we can quantify how “green” a freight train is.
One lorry will take up a lot less space than a dozen cars, so if giving a path to a freight train means taking “x” lorries off the road but putting “12x” cars onto the road then you’d have to assess whether the trade-off was worth it.
We’re not dealing with BR-levels of demand, where there was spare capacity for randomly timed services. Lines are congested, and running non-standard services is a poor use of the capacity we have (that may mean attempting to slow down non-stop services or speed up the slowest services, or potentially remove either, but capacity is much better used where we have relatively “uniform” speeds/ service patterns).
Take a situation where a freight train from a docks (e.g. Felixstowe) to a distribution centre (e.g. Trafford) passes over Anytown Junction at 11:03. In today’s clockface railway that means that the equivalent paths at 10:03. 12:03, 13:03, 14:03 etc are also blocked out to passenger services (i.e. providing that path for one freight train may be at the cost of several passenger services spread over the day).
And then there’s the fact that a Felixstowe – Trafford freight is generally going to return to Trafford empty. Whereas a logistics company like Currie/ Wincanton/ Stobart isn’t going to want to run hundreds of miles empty, so will try to link this contract to a job requiring them to convey goods from Greater Lancashire down to Greater London (since they’d have to pay for the drivers/ fuel anyway, the marginal cost of filling the lorries at another warehouse near Manchester and driving back to a different place near London isn’t going to be as large). Logistics companies use their resources as tightly as they can – an HGV might do a round trip of London – Manchester – Bristol – London. Railfreight is more “there and back”, hence the number of “empties” we have on the rails. A lorry firm couldn’t afford to run half of their mileage as “empty”.
Plus, pretty much all freight is diesel (even if it spends the vast majority of its journey under the wires), whereas passenger trains taking the paths freed by freight could be (much greener) EMUs, which is another environmental consideration.
So it’s not as simple as looking at a freight train and triple-counting the wagons and saying that it’s taken that many lorries off the road. You’d have to look at the number of passengers who could use the same slots (and the number of cars that that would take off/ put on the road). You have to consider the bigger picture.
Freight trains are great, I’m all for things that are better for the environment.
But there’s a point at which taking one freight train off the railway (and putting dozens of lorries on the roads) will be better for the environment
if it means significantly more cars come off the roads (because we can run several electrified passenger trains with the capacity freed up by to accommodate one non-standard path taken up by a 100% diesel freight train).
And, to be blunt, if putting a hundred lorries on the roads takes over a thousand cars off the roads (because of the improved passenger services that could run if they weren’t constrained by freight) then maybe that’s a trade-off worth doing. And, maybe, having hundreds of lorries on the roads (slowing down motorways) would make the roads less attractive to car drivers and encourage them onto the rails too? Not black and white.