Need for an'all risks' delays cover to travel insurance?

An 'all risks' delay policy would be a big help to travellers. You get standard cover against certain causes of delay: strike, mechanical failure of your car, etc.
If however you're delayed because of a pile up on the motorway you are not covered as my friend found out to her cost at Bristol airport 20 mins too late having allowed 2 hours for a 5 hour journey.
We too got delayed, in Paris after an escalator failed at Gard du Nord caused a massive build up during a busy period; somebody's walking stick had got jammed and threw the emergency stop gear. We weren't covered for the loss from that delay. Luckily we'd
allowed a massive contingency in our programme.
So both events were documentable, thus provable, and anyway are insurable risks, yet you cant get cover. . The idea of insurance being written on the assumption of 'utmost good faith' is accepted in house insurance, but not it seems to travellers. This is a gap in the market which travellers need covered.