Should I contact police to tell them I was overtaken on a 60mph road about 120mph - and then there was a crash?

I did, I was going down a country road when some loon (and his chums) overtook me going much too fast where the road narrowed over a bridge to one lane. Had to do an emergency stop or run him into the side of a stone bridge. Part of a German car club who were doing a driving tour of Scotland. Conveniently had a big sticker and a website.

The police came and took a statement, there had been a crash a decent bit further down and the previous day, they’d posted the upside down car with happy faces on the website. Said it’d be useful, didn’t hear any more about it though.

I would report it OP. Somebody went into the back of us, while we were slowing down to get into the queue to exit on a slip road on a dual carriageway. We stopped to swap details, and the other driver just reversed and drove off at high speed. While we did get their number plate and reported them to the police, we would have appreciated it, if a witness had also reported it to the police - even if it was just the colour of the car!

This.
The defence will argue that you didn’t see the plate and could have been another car-but let the police decide

Yes, I think its your duty.

@CorduroySituation thank you, not a day goes by where I don’t think of him.

I’m sorry for your loss too.

There are too many idiots on the roads and the laws just aren’t strict enough xx

I'm so sorry for your loss. I lost a relative to a drunk driver, I feel for you.

Do we assume OP has given up on this one?

Definitely tell them.
It might help and it might not but let them have the info.

Another vote to tell the police OP. A close family member was killed in an RTA where the driver was jailed for causing death by dangerous driving. One of the witnesses in court gave evidence similar to what you've witnessed and it helped secure the conviction.

Have you reported it yet?

If not, phone 101

Calls to the police 101 non-emergency number are free, no matter how long the call, what time of day it is made or whether it is from a landline or mobile phone ..

or alternatively, for a road traffic incident:

www.police.uk/pu/contact-us/a-road-traffic-incident/

Definitely report to 101. It could help them with building a picture of what happened prior to the accident.

As I think I know where this happened, you can even contact the police through their local facebook page and they will respond quickly.

Yes absolutely

Yes I reckon you should. You have idea of car colour and shape, types of manoeuvres and impression of speed. Maybe time it happened too. They will decide whether to disregard or not .
must have been scary x

Yes. Let the police sort out of it’s relevant.

You have more information than you realise - you know it was a dark coloured saloon - it’s a piece in the jigsaw puzzle they are trying to build

Yes, call and give your account, just the facts. They can match the rest up with cameras and the rest of the incident details depending on what they have available.

You should definitely report it. The car that overtook you might not have crashed — it might have provoked the later crash as people tried to avoid it. The police will be looking at CCTV to see where various cars were and when, and if you can pinpoint the spot and time this might be critical information for linking two CCTV images.

The manner of someone's driving before an accident is really important key information.

Im more of a holy shit what a fucking idiot person rather then a gasper.

@squashedbananasagain please tell the police, my brother was killed by a speeding driver and witnesses had seen him speeding way before the accident and they all thought he would kill someone that night and he did

Yes, of course you will let the police know. You are a potential witness - they will decide whether potential becomes actual. I honestly cannot think why you wouldn't call the police on the non-emergency hotline (101). If that car doing 120mph had hit you, you probably wouldn't even be alive to ask this question. You'd want someone half a mile back to report seeing it, wouldn't you?

Ring 101 or report online.

I once was overtaken on a 50mph road in Wales by 2 idiot cars going maybe twice that, single carriageway.

Like you, a few miles down the road both cars were impaled on a wall. The police had arrived by that point and were over-run with folk who had stopped to tell them what idiots they had been.

I would, you might be the only witness who can confirm that a dark coloured saloon car was driving dangerously on that stretch of road at that time, which combined with other evidence could help the police put together an accurate picture of what happened. That would be particularly important if there are any victims of the crash because it would help bring closure to them or their families.