As stated above, the 405 freeway is probably the busiest freeway in the United States. As it is, the 405 participates in two of the top 10 busiest freeway interchanges in the United States, based on an article I saw published on CNN. First, the 405 / I10 interchange, and secondonly, the 405 / US101 interchange. For about 7 years, I had the distinct pleasure of having to drive across both of these interchanges to and from my job.

For years, as I left work I would view a traffic condition website maintained by a company that was contracting with CalTrans at the time. The website would show a map of the LA area freeways, with a red, yellow, or green dot every mile or so indicating that the traffic along that stretch was either poor, pretty bad, or "better" than pretty bad. (note: These indications are subjective and tend to take into account the relevant overall conditions on LA freeways. For instance, I've been in other parts of the country where rush hour traffic density on the highways would warrant about 80 mph in LA, but the drivers were all going 55 because traffic to them was "bad".) Needless to say, any day where the stretch of the 405 that I needed to drive wasn't 100% red dots and had any yellow dots at all was a good day.

As indicated by the above, the 405 can barely handle the peak traffic demands placed on it, and that's when there are no problems. Road construction (which always seems to occur at the most illogical times), an accident, a stalled car, or anything else that causes the closure / blockage of one or more lanes can cause utter havoc and traffic backup for miles. This is true even at non-peak times and late at night.

Recently, CalTrans has been working to add lanes to stretches of the 405. They have elected to add carpool lanes instead of general use lanes.

While carpool lanes are a good thing, in theory (since they should encourage fewer cars to be on the road and thus ease conjestion), the truth is that they are disasterous. First, on the 405 there is virtually no enforcement of the rule that to drive in the carpool lane the vehicle must have at least two people riding, - <opinionated level=high> carpool lanes should not be designated as such unless the police can do an adequate job enforcing the rules - why the police can use automatic sensors to enforce red lights but not use sensors to enforce the two passenger rule is beyond me</opinionated>. Second, the carpool lanes are dangerous - on the 405 the carpool lane is adjacent to a concrete barrier on one side, and what is often the equivelant of a concrete barrier (a wall of cars barely moving at all or moving MUCH slower than the cars speeding by in the carpool lane) on the other - carpool lane users do not have options to avoid accidents (such as swerving) that are often available to users of other lanes - as a result they promote rear end collisions. Finally, carpool lanes tend to penalize people who cannot often have a second person with them. If a carpool lane does not reduce traffic conjestion for everyone more so than traffic conjestion would be reduced if the lane was a normal use lane, designating the lane as a carpool lane is not justified.