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Sustain to gain: November 2010 Archives

As scientists modeling sustainable urban transport, we are confronted with a significant conundrum.  On the one hand, non-motorized transport (NMT) comprises the most sustainable modes. Neither walking nor cycling emits GHG emissions, nor does it contribute to air pollution, nor does it produce noise externalities, nor does congestion result from NMT activities. Hence, we are of course interested in understanding what incentivizes NMT, and how the modal share of cyclists and pedestrians can be increased while satifying mobility demands. On the other hand, however, the literature on incenvizing factors of NMT and crosselasticities between other modes and NMT is sparse. This is to some degree because investments and political attention go into motorized transport. NMT is mostly handled as a given that will find its place, and does not need further attention. Furthermore, monetary costs of motorized transport make motorized transport an accessible object for transport economists. The intrinsic non-monetary nature of NMT make incentives much harder measurable - a considerable knowledge gap results. As sustainable urban transport gains more attention, pedestrians and cyclists shift into the spotlight.

A recent study of Montreal cycling by Larsen and El-Geneidy helps to shed light on the relationship between bicycle lane availability and attractivity of use.  These are some of the main conclusions:

  •           Recreational cyclists are more likley to use bicycle facilities (e.g. bike lanes)
  •           Frequent cyclists use lanes less and travel greater distances
  •           Greater separation of bike lanes from vehicle traffic - e.g. by bicycle alleys - increases trip distance
  •           Connectivity of the network matters: The longer bicycle lanes are, and the better they are connected with other bicycle lanes and facilities, the more attractive they become for users

The authors conclude by suggesting that physically separated bike lanes are best to encourage novice cyclists. The connectivity of a bicycle network may, however, be the most important design and investment criterion.

It would be very interesting seeing more studies on this topic. What is, for example, the cost-benefit relation of different kind of bicycle facilities (measured in $ infrastructure investment versus marginal increased bicycle use)? How does this cost benefit relation change as a function of bicycle network connectivity? Can these results be generalized to other cities? 

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Abundant newspaper analysis point out the higher costs of renewable energies (e.g. Cost of Green Power Makes Projects Tougher Sell, New York Times, 7 November). However, both industry employees and economists who analyse intertemporal dynamics understand renewable energies to be long-term cost effective and socially desirable. What is the source of this conceptual divergence?

A recent paper by Christian Breyer and colleagues highlights a possible source of this divergence, by looking at the photovoltaics (PV) industry (Breyer et al., 2010). Cost reduction is mostly influenced by growth rates and technological learning curves. A technological learning curve shows the cost reduction achieved by technological progress, economics of scale and market volume growth. Annual growth rates for PV have hovered around 30% for the last three decades, learning rates at 20%. Hence, initially PV was economically unviable but can by now successfully compete on an industrial scale at geographically advantageous locations, and within a few years, in Western Europe and the northern US as well. In contrast, conventional electricity-generating technologies have lower growth rates, lower learning rates, or – in the case of nuclear energy – may even have negative learning rates (Grubler, 2010). Meanwhile, PV achieved a manyfold cost reduction with only 2% of the R&D costs of nuclear-power plants.

There is possibly a deeper explanations underlying these observations. PV is a highly sophisticated technology that relies heavily on knowledge, experience and research but less on resources. By contrast, economies of scale for nuclear and fossil-fuel technologies are fundamentally bounded by their respective fuels. In fact, because they are resource-based technologies, conventional technologies are more subject to decreasing returns to scale, whereas PV as very knowledge-intensive technology is more subject to increasing returns to scale.

Another crucial property of PV – in comparison to coal and nuclear power plants – is its modularity and also its lower energy density. As a result, PV allows for and requires many agents (including homeowners) and diffusion over many sites. Interestingly, rent seeking by investors can be (but is not necessarily) more equally distributed across the population, contrasting with rent seeking of a few highly leveraged investors in resource-based, conventional technologies. This opposing view of not only environmentally technologies, but also of socially desirable economic systems, is exemplified by the recent protests and demonstrations around Gorleben in Germany, with thousands of people blocking a nuclear-waste transport in cold November weather for several days and nights (Despite Protests, Waste Arrives in Germany New York Times, 8 November).

The first impression of an East European city such as Poznan or Krakow in Poland, Chişinâu in Moldova, or Sofia in Bulgaria is that of old crumbling public transport systems and unrenovated housing stock in Soviet stilo-style packing. Indeed, the majority of inhabitant strife for higher material well-being, in particular within the service industry (e.g. education and public health) which pays rather low salaries and is decoupled from gains in the rent economy.

Nonetheless, East European cities maybe considerably ahead in crucial aspects to their Western counterparts. Their public transport system is comprehensive, and public ridership consistently high. In Sofia, the 1.3 million people large capital of Bulgaria, distances within the city center are walkable, and access to peripherical parts of the city is mostly guaranteed by low cost tramways and busses.

As a side effect of a high modal share of public transport and walkable distances, the inner part of the city is full of people, making public space enjoyable and relaxing. Indeed, as Jane Jacobs put it:

"Under the seeming disorder of the old city, wherever the old city is working successfully, is a marvelous order for maintaining the safety of the streets and the freedom of the city. It is a complex order. Its essence is intricacy of sidewalk use, bringing with it a constant succession of eyes. This order is all composed of movement and change, and although it is life, not art, we may fancifully call it the art form of the city and liken it to the dance – not to a simple-minded precision dance with everyone kicking up at the same time, twirling in unison and bowing off en masse, but to an intricate ballet in which the individual dancers and ensembles all have distinctive parts which miraculously reinforce each other and compose an orderly whole."

Jane Jacobs (The Death and Life of Great American Cities)

These East European compact cities with old, sometimes slow, public transport, came out of the Soviet era – and though of course are results of a planned economy, their form is also rooted in a lack of resources to build a car dependent infrastructure. The built environment reacts slowly to external forces, and the historical circumstances induce a path dependency of the land-use transport interaction. As a collateral, GHG emissions of urban transport is relatively low. Furthermore, future oil price rises, as for example anticipated by the IEA, may cause little effect on the urban functioning of these cities. As such, East European cities may be more 'resilient' then more car-dependent (and richer) West European cities.

Surely, it is social romanticsm to indulge on existing infrastructures. To stay with transport, bicycle networks are not (yet) existing or very purely implemented, a relatively small number of cars, coming from more distant suburbs swamp the city and cause safety issues for non-motorized transport (NMT), and noise and air pollution. Parking management, though formally in place, lacks enforcement, and wild parking causes considerable congestion and inconvenience for pedestrians who walk on sidewalks that sometimes more resemble adventure parks.

Even considering these considerable draw-backs, the overall perspective is differentiated. While East European cities surely can improve on NMT infrastructures, modern public transport stock, and car regulation, it is West European cities that are more vulnerable to external shocks, and can learn to some degree from Eastern transport land-use models.