Wednesday, April 19, 2006

Solving the traffic congestion problem

I should probably stop being amazed at what comes as an excuse for 'reducing traffic congestion'. The problem is simple: Too many cars on the same roads at the same time cause trips to take longer and cause pollution. The 'solutions', however, are where the problems usually arise.

If the goal is to reduce pollution, having the highest emitting vehicles on the road for the least amount of time would seem like a good solution. So we should have express lanes for high polluters, while letting the low polluters sit in traffic for a while. However, the opposite is done. The low polluting hybrids can use carpool lanes, thus allowing them to move quickly. However, they would emit the least pollution if they were stuck in traffic. Meanwhile the high-polluting SUVs and trucks are sitting in the slow lane, spewing out a huge amount of pollution.

Ok - the desire of allowing hybrids to use the 'fast lanes' may not be to reduce the local pollution, but instead to encourage more people to drive 'less polluting' vehicles. However, if that is the case, why do the roads that have the carpool lanes often prohibit the least-polluting vehicles. Pedestrians and Bicycles pollute much less than even the most efficient cars, yet they are barred from the freeways. Meanwhile, high polluting cars are permitted. If the policy was to encourage the most efficient vehicles, why not flip it around and ban any car that is in the top 25% of emitters? Or perhaps even factor in passengers, and restrict it based on emissions per passenger.

Another factor is travel speed. This is the factor that tends to be most visible to people. If their commute takes longer, people get upset. Methods for reducing commute time include expanding and 'upgrading' roads and attempting to reduce the number of vehicles traveling at peak times. Expansion and upgrading of roads can be problematic for psychological reasons. As congestion increases gradually, people can gradually grow to expect the commute to take longer. They become acclimated to a longer commute, while at the same time, they lobby for improvements to reduce the congestion. The improvements get made, and the commute time is briefly shorter. However, they have already become acclimated to the longer commute, and are thus willing to travel an even greater distance because it can now be made in the same amount of time as previously. Soon congestion worsens and the cycle repeats.

Improvements also have their collateral damage. New lanes take up space. That space can no longer be used for other purposes, thus spreading out other development and increasing trip lengths. Furthermore, limited access freeways have limited access and limited crossing. As roads are upgraded, some trips to access them may be longer. Some users may be shut out of roads, and some shuttered cross streets may cut off access, or increase trip length. Car will generally add distance to their trip to access the freeways, while some non-car trips will be eliminated. Even small 'improvements' like adding sensors to intersections or giving long light-cycles to main streets will reduce access at cross streets. In addition to slowing these trips it can discourage what would be short non-car trips, and transform them to car trips.

This leaves the option of moving people out of their cars. It seems a carrot or stick approach could be used. The bridge tolls are a carrot approach. However, they have significant flaws. If you drive in a carpool during rush hour their is no toll. However, there is no incentive to carpool outside of rush hour. Thus, car pools our encouraged to travel during peak travel time. Furthermore, carpool lanes are only in effect during rush hour, thus a carpool that could easily travel outside of rush hour is encouraged to travel during rush hour for possibly faster travel time, and lower tolls. Similarly, drivers in carpools have an incentive to travel at 8:30 to use the carpool lane, rather than 9:00 when all lanes open up.

There are also attempts to encourage people to use public transportation. In New Jersey, they wanted to encourage transit as opposed to bicycles. The rationale being that the roads were too dangerous. Of course, most job areas in Jersey are suburban office parks, while the commute to New York and Philly are often made by people driving to park and ride lots. Thus, transit use is part of what is making the bike commute 'dangerous' in their eyes. Furthermore, the most viable transit use is to support out-of-state businesses. (Last year, I stayed at a hotel in Seacaucus, New Jersey. Though it was quite close to the Newark airport, the transit service to EWR was quite limited. On the other hand, there was frequent transit service to Manhattan, and it was easier to make the long transit haul from LGA than the short trip from EWR. The bus traveled from the New York bus station to a giant park and ride, and then on to the hotel area. Both the park and ride and hotel area were fairly isolated and surrounded by freeways, thus allowing very little easy non-vehicular access.)

Transit in Santa Clara county is also problematic. VTA has relatively high fares, especially for the level of service provided. (A base fare of $1.75 with no transfers available.) It also has an extremely low farebox recovery ratio (in the teens). The system is primarily low-frequency, slow suburban bus service, with some express bus and light rail service. A switch to transit will in most cases entail a slower commute, and put more restrictions on travel time. The trips may also be more expensive. (Even more so if the huge VTA subsidy is factored in.) In most cases, an individual commuter could save time and money by driving alone.

A core problem with transit is the sprawled out nature of development, and the low cost of driving. Furthermore, in spite of the huge cost of land, parking reigns supreme. Sunnyvale requires all houses to have four parking spaces (two indoor and two outdoor), yet it still is reluctant to do anything that would reduce on-street parking. (Bike lanes on Homestead are only part time in order to preserve parking.) A homeowner on The Dalles was prevented from expanding their home because of the increased inside parking requirement :
The rationale was that they could not grant a reduced setback of 14 feet for the property, even though the neighbors had no problems. Ironically, a few blocks away, a house freely exists with zero setback from the sidewalk. However, this must be ok because the actual 'front' of the house is not on that sidewalk. And Sunnyvale even requires remodeled homes to add to the car space ( However, in these ordinances there is no mention of the number of cars owned or used. They just want to reduce on-street parking. Why not just charge for on-street parking? That would probably do much more to reduce the cars parked curb-side. Or better yet, just make them no-parking zones. That would be a much cheaper way to reduce the on-street 'clutter', as well as allow for expansion of sidewalks and bike lanes.

Silicon Valley is 50% residential, 20% commercial/industrial, and 30% public (roads, parks, schools)
It would interesting the calculate the huge subsidy that is given to cars in the form of the parking requirements.

It's interesting to see the parking requirements that Sunnyvale has:
The few carrots - parking at businesses can be cut by 5% if bicycle parking and showers are available.

What if the city set all current minimums as maximum parking? And required 50% of it be devoted to bicycles? And required homeowners to buy 4 bikes instead of building 4 parking spaces? You would have a lot of people really angry at a change in the status quo. But, you would also do a lot to reduce the demand for car trips. However, other changes would need to be made. Zoning must be improved to put more people close to their work. (Office and retail space should be near residences.) Schools must be improved. (It's ironic that many of the Sunnyvale schools are leased out to private schools. The schools are bad, put children still need to be educated. So people pay taxes to the school district, and then pay tuition which also goes to the district in the form of rent. And they get nothing out of it. Meanwhile their neighbors have poor public schools that they must attend, where they spend most of the time testing instead of learning. What if the school district was required to reimburse tuition of any in-district in-former-zone student attending the private school? This could reduce the congestion around the school, and provide for better learning experiences.)

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