Re: Hanlon's razor
Another reason for more traffic. Ministers have been pushing Construction to continue regardless throughout this period (hence the photos of all the construction workers trying to get on the tube).
Many companies shut their sites for a few weeks, but with a combination of financial pressures and the contractual risk of being sued by clients (of course you could have continued to work, the government said so!) they are now opening up more and more sites.
Depending on what related trades you include, construction is 5 to 10 percent of the economy, so a lot of commuters and traffic.
Many of these are low wage people as well, so unlikely to have enough savings to be able to be picky about offers to go back to work.