There's a point, halfway across the bridge, where I leave one county and move into another, where I cross from the world of work into the land of living.
The traffic is almost always heavy at this point, so we crawl across, nose to tail; a long line of blinking brake lights, like a Christmas garland draped across a mantelpiece. Below me, instead of a fire place, is the river. On my right it stretches into the magical distance of London town; where the tall towers of Canary Wharf compete with the bullet shaped Gherkin to grab the skyline and my attention. I can't see Millbank Tower but I know it's there, just a bit further along; reminding me of the days when I worked on the 17th floor and looked out every day on this same river.
This is the last bridge before the sea; below me, the slow muddy water makes its way to the ocean. It meanders on past Tilbury docks; where passengers wait patiently for the cruise ships to pick them up and transport them to other ports of call in settings more sublime.
As I creep into Kent. I peer at the warehouses and factories laid out on the riverside. I see a line of lorries, decorated in their bright corporate orange-ness, waiting to be filled from the depths of a distribution depot, and I realise I've never actually seen anyone entering or leaving the vast shed. I look at the grey factories and smoking chimneys, wondering what goes on behind the brickwork. Are there people in there working the evening shift, looking up at all those cars on the bridge above, envious that for some of us, the day's work is already over?
Usually, this is the point where I leave the worries and frustrations of my working day behind. I start to relax as the car crawls slowly towards the toll booths that mark my return to the south of England, the place I know best.
Today though, I barely notice the bridge or my journey over it. Today, just as I reach the halfway point, my phone rings, and the voice in my headset tells me excitedly that Blogger has made me today's Blog of Note.
And now, there are no thoughts of work to exorcise from my brain, no weary anticipation of dinner and sleep. My mind is whirling, I'm thrilled to bits by the thought that people might come to read my blog for the very first time, that some of them will come back again. I know already that I'll get to read some great new writers that I just haven't known about before. I can't wait to see who they are.
Today, halfway across the bridge doesn't seem like the escape point from where I'd rather not be; it feels like an entry to a whole new world.