My shoulders are hunched, my palms are sweaty and my systolic blood pressure has just passed 170 -- about the level found in fighter pilots' flying training missions. But this isn't a war zone; this is morning rush hour on the A360. The driver behind me blasts his horn and my pulse rate jumps another few notches. I feel stomach cramps coming on.
I have exactly seven minutes to get to my meeting and all I can see is a stationary line of cars stretching ahead. I slump over the steering wheel, the will to live just about lost.
According to occupational health expert David Lewis, I am now suffering from acute stress. "All the signs are there," he says. "Raised blood pressure, tense posture, excess stomach acid. Because of the noise, aggression and obstacles around you, your body is flooding with the hormones adrenaline and cortisol, preparing you to fight or flee. Unfortunately, you can neither flee nor fight when you are sat in traffic, so all that stress is bottled up."
But could this drive have long-term effects on my health, my work and my home life? Are the millions of people who drive to work every day doing themselves any lasting damage?
Lewis thinks so. As we crawl, at about 8kph, across Hammersmith Bridge, he says: "Every minute spent in heavy traffic impacts on every other aspect of a person's life. Many people waste hours in the office every week while they do little more than recover from the stress of their commute. After the drive back home, they may be so tense that they drink more than they should, act aggressively towards loved ones or have trouble sleeping."
The UK's roads are packed. There are around 32 million licensed cars in the UK, compared with 9 million in 1961. Traffic flows have increased by one-fifth in the past 10 years and continue to rise by 1 percent to 2 percent a year.
1. Do it less often:
Many employers still want their workers where they can see them. But Graham Lucas, of Primary Healthcare, says: "Many people would actually be far more productive if they were allowed to cut out wasteful, stressful travel and work from home a couple of days a week."
2. Create a decompression zone Stress expert David Lewis says: "Fighting your way through traffic will build up stress hormones. If you jump straight into work or family problems, those hormones will stay with you for hours, making you perform badly at work and irritable at home." After you reach the office take, 20 minutes to do nothing other than unwind. After you get home, park the car and walk around the block to dissipate all the excess adrenaline.
3. Stop the clock:
Don't say "See you at 9.45," say "I'll see you when I get there." Lewis explains: "There are hundreds of variables outside your control that affect when you will get somewhere. So don't create deadlines that you might not keep through no fault of your own. A little bit of flexibility reduces stress hugely."
4. Avoid rush hour -- but not by working longer:
Working earlier or later in the day can help you beat the worst traffic. But don't do both. Lewis says: "Too many people go in early and then end up staying late. They may miss rush hour but they have only made things worse because tired people get more stressed and are more likely to have accidents."
5. Treat your commuting hours as valuable time:
"Anxiety multiplies because of the idea that you are wasting time," Lucas says. "Thoughts like `I could have written that report by now' or `I could be sitting down with a bottle of wine' create stress. So take the chance to listen to a CD you rarely get time for at home, or alternatively listen to the recorded version of a novel you have always wanted to read."
It all equals a growing public health problem. In one study in which Lewis was involved, drivers dealing with heavy traffic were found to have similar systolic blood pressure -- up to 180 from a resting rate of 120 -- to that of fighter pilots and police taking part in simulated riots.
"Fighter pilots and riot police are trained to deal with their stressful environments, whereas drivers are not," Lewis says.
We reach Hammersmith roundabout at around 9am. A motorbike darts in front of me, causing me to brake hard. I use my horn to (gently) remind the rider that his manoeuvre was dangerous.
Lewis says the density of traffic around me explains why my breathing has become quick and shallow and why I can feel palpitations in my chest.
"Your stress spirals in any situation where you are not in control. Driving is paradoxical because you feel you have a lot of control over your car, but in fact your speed and trajectory are strictly regulated by other traffic," he says.
"You have put yourself under clock pressure by setting a time for the meeting, but it is outside forces that determine whether you get there on time," Lewis says.
And they have determined that I should be late. At the red lights, I creep forward to close the 30mm gap between me and the car in front.
Lewis, a fellow of the International Stress Management Association, points to my hands, which are fidgeting on the steering wheel and to my legs, which are shaking slightly. He tells me that many drivers are so used to these kinds of symptoms -- as well as more serious ones such as dizziness and nausea -- that they barely notice them any longer.