Stephen Rees's blog

Thoughts about the relationships between transport and the urban area it serves

Archive for September 13th, 2007

Gateway’s air-quality impact questioned

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Vancouver Sun

Regional district division manager Roger Quan said Wednesday a provincial environmental impact report that predicts “negligible” impacts on air quality fails to take into account the growth that could result from the Gateway project itself.

There are actually two effects here and they are difficult to separate. But the model used to forecast transportation demand does not take either into account.

The model has no “feed back” loop. Although it calls itself an land use/transportation model, it cannot do anything within itself about land use. That is treated as an “exogenous variable”. In other words, the user inputs the land use data. This in itself is a very crude process. Each zone in the model has a land use associated with it – residential, employment, retail. The amount of travel is expressed a number of trips between zones, and that depends mostly on their size and the distance between them. But for any one scenario, the land use is the same for each year modelled.

What this means is that the future year’s land use is exactly the same, no matter what has happened to the transportation network in the interim. When comparing future scenarios, the model is solely concerned with distribution of the fixed number of trips across the network. The origins and destinations of those trips in the model do not change.

This is very unrealistic. Ask anyone in the real estate business what determines property value and they will reply “location, location and location.” If you make significant changes to the transportation system, you change the accessibility of locations. Transport is a derived demand. Very few trips are just for the fun of the ride – although that is now less true than it once was. But demand for motorised travel is strongly influenced by perceptions of generalized cost – not just how much money it will cost, but how much inconvenience and delay will be experienced. Some destinations will get a very high perceived cost. For instance, Cambie Street has become a very much less attractive recently due to Canada Line construction, and a lot of discretionary travel has diverted elsewhere – especially shopping and visiting restaurants.

The Gateway project will change perceptions of travel time. The barrier effect of the river crossing will be lowered, and the province’s proposal to use a flat, low rate of toll ($2.50 a trip in the forecasts, if not in reality) will have little impact on this. After all that is less than 5 minutes of delay time at average hourly wage rates, and much less at higher income levels.

The two effects I referred to are short term and longer term. But they overlap. In the short term, the day the new facility opens, the sudden increase in capacity available is much more than previously used, so there is a period when traffic is flowing freely. This does not last long. In fact, opening day may not see it just because of the novelty value. But very quickly travel patterns change as people start to use the new opportunity to travel to places and use routes they formerly avoided due to the congestion. More trips are now made and they will be longer (in distance terms, not time) than before. This is “generated traffic“. It always happens, especially in city regions currently experiencing congestion. Some trips are currently not made at all – suppressed demand – because they are “not worth it”. Increasingly we can do shopping on line, or download a movie. So we go to the shops and the cinema less. We can combine trips, to lessen the impact of wasted time. Once the new capacity becomes available there is less incentive to take these options.

The second effect is the one that Roger Kwan refers to. Land use starts to change in response to the new capacity. Freeeways have this effect even in their planning stages and speculators have already started to buy land in the valley in the expectation of the new freeway capacity. The province argues that this development would have happened anyway. But this ignores the impact that new freeway capacity has on perceptions of travel time. It changes the pattern of development in terms of its location and density. This induces more travel. The pattern of development is not transit or pedestrian oriented, but freeway oriented. The pattern of driving to every destination is reinforced and the “no alternative” reason for car use spreads ever wider.  The province argues that the municipalities can influence these patterns, which is true but a very partial perception. Port Moody allowed lots of new dense development in anticipation of a light rail system that is still not yet built. They won’t make that mistake again. Surrey and Langley have been allowing lots of highway orientated development. Strip malls. Big box stores. Low density subdivisions. Lots of protected green space in between them too. Indeed that is one of the reasons that highway expansion is now “needed”, even though the Province and the Gateway advocates like to pretend it is for freight.  The DNA of the suburbs is different from the streetcar oriented development patterns of the much older parts of the region like Vancouver and Burnaby.

The suburban sprawl of North America is far worse than is seen in Europe, because our land use controls are much laxer, and developers have ways of influencing development here that are less usable in other countries. The interstates were supposed to be about long distance travel, but their impact has been much greater on commuting patterns. Building freeways through the downtown cores was the worst mistake, and one which Vancouver avoided. Widening freeways, and twinning bridges, is the next major error, since it reinforces already established patterns when what we need to do – for a wide variety of reasons but reducing ghg emissions is currently the most significant – is to change behaviour. Not reinforce it.

Mike Proudfoot, executive director of the Gateway project, says that recent government initiatives, including the adoption of California tailpipe-emission standards and clean-air retrofits for commercial trucks, “will only improve the situation.”

Which again may be true – but that should be done in any event: it does not a new freeway to justify it. There is also a neat confusion here between local air quality (tailpipe emissions of common air contaminants) and greenhouse gas emissions. You can burn the same amount of gas but remove more of the NOx and particles, or you can burn less gas. Certainly tighter fuel efficiency standards would help – as will smaller cars and more hybrids. But that is not what Proudfoot is talking about. And making fewer single occupant vehicle trips is a much more effective strategy – for both greenhouse gas reductions and improving local air quality. Not only that but spending about a third of the cost of the freeway expansion and bridge twinning by expanding transit service, would not only be much more effective, because it will allow people to switch from driving, but also would work faster – because we could start right now, and not have to wait until the end of the next decade to see the results.

Written by Stephen Rees

September 13, 2007 at 8:49 am

High-density development can create ‘urban heat islands’

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Energy Bulletin Sept 11

“Heat Islands” may produce more energy consumption – or not. First of all, it depends on the ambient temperature, and how comfortable it is. Secondly how people behave.

I suspect there is a significant difference in Phoenix to downtown Toronto for example. But also some of these effects can be offset by techniques such as green roofs, better energy efficiency in the buildings (less heat loss) use of planting and landscaping and so on.

But mainly mixed land uses, so the people in the buildings do not feel quite so much need to drive everywhere.

Moreover “may add to global warming” also depends on the energy source and use. In a city like LA which gets a lot of its electricity to run HVAC systems from coal power, there could well be an increase in carbon emissions. But somewhere using existing hydro (like Vancouver) no increase in carbon emissions.

Many modern office buildings capture all their own “waste” heat – people generate a lot, and so do copiers and computers. If you have a dense urban core, mixed land use and a district energy system this heat can be used by other buildings in the vicinity, such as care facilities. North Vancouver has such a system in its new development at the south end of Lonsdale. Of course such places need careful urban planning.

So LA and Phoenix, with very low densities in general, poor transit systems, low energy efficiency buildings (a legacy of a long history of low energy prices) and the custom of not only having the a/c set to deep freeze but also sending the “waste” heat into the sky, probably do add to the problem. In a city like Toronto where there is significant need to heat many buildings in winter, but plenty of “waste heat” around which can be captured, plus a good transit system and much mixed land use near the core, the effect may not be so significant.

Of course, systems such as LEED are fairly recent innovations in North America, but rising energy costs mean that better buildings pay for themselves in lower operating costs. Lots of surface parking lots, paved with asphalt also create more urban heat effect than parks, planting and other urban amenities.

In Vancouver, our biggest issue in meeting the current challenge of reducing emissions is mainly going to be about transport. That is because we no longer have the large scale industrial users in the city. Indeed, BC has a much bigger challenge than say Alberta – which Vaughan Palmer pointed out yesterday. Our challenge is to reduce ghg emissions from driving ourselves around: some of that will come from better, smaller and more efficient cars and maybe better fuels. But much more can come from significant investments in transit – given that our transit system is over capacity and a lot more people want to use it than can. But mainly not building more freeways to encourage ever more low density sprawl up the valley and outside the Metro area and creating more motorised travel demand. “Build a compact urban region, with complete communities, protect the green zone and increase transportation choice.” (LRSP) That was a good formula before Gordon Campbell committed us to a 30% reduction in ghg – it is an even better one now!

Written by Stephen Rees

September 13, 2007 at 7:17 am