Google Maps/Streetview - Westminister Bridge.
Sometimes, we look for complex 'terrorist reasoning' why someone did something when it can be the simplest, the most straightforward reasons that can get overlooked.
Things that cause frustration and people to snap, and our daily reliance on technology to get things done.
Driving in London is frustrating, especially without working Sat-Nav.
If Khalid Masood was simply trying to find a particular location, one of the interesting things is that using Google Maps (in a web browser at least), just at that key point where Khalid Masood 'flipped' prevents you from crossing Westminster Bridge on that side of the road.
(Click the arrow one place forward on Google Maps/Street view, to see you are prevented from continuing on that side of the road). You have to move to the right lane, to use Google Maps/Streetview (traffic heading towards you to cross the bridge) using the mapping.
Maybe Google maps has being restricted to prevent showing the bridge since the incident.
An interesting anomaly, all the same.