
I must have walked past the Carriage Gates to Parliament thousands of times. There's always police there and they present a friendly face whilst only allowing the permitted people inside.
My pictures here were only taken a few days ago.
The whole area is swamped with tourists for most of the year as well as plenty of people going about their business. The gates can be an area for tourist photographs, although there's also a priority to get cars usually containing ministers and high profile folk inside quickly because of the exposure.
Seasoned inhabitants of the area stride purposefully and can probably walk at about three times the speed of the tourists blocking the pavements.

Like many locals, I'll also select the west side of Westminster Bridge to walk across when going towards Waterloo. There's probably five times as many people on the other side of the road most of the time. The west side was the one used by the lunatic driver.
So when I saw the first tweet and then the periscope.tv unfolding of events on the bridge and at Parliament Square, it brought home the delicate balance of the systems that we all take for granted.
As a Londoner, I've been used to bomb threats, watching out for un-tended luggage and all the other signs of potential unease. We always had bomb alert protocols for our buildings, including what to do if one received a threat. We've been evacuated a few times too, over the years and had that Run, Hide, Tell drilled in.

Parliament itself has also had increasingly stringent security imposed. There's the concrete chicanes along the front of the building and for the access to the Lords' car park area. There's also routine armed police with big guns all around the building, with a finger resolutely pointed along the edge of the trigger guard.
Despite whatever the authorities can do (for example there's huge metal turnstile type bollards at the end of the route that the attacker took across Westminster Bridge) there's still a practical limit. The depraved perpetrators of these incidents use motor vehicles and kitchen knives to inflict death and destruction.
London will largely be back to its own amazing version of normal today, aside from the minute silence at 9:33 and tonight's vigil.