| 1. |
- Almroth, Andreas, et al.
(författare)
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Further development of SAMPERS and modeling of urban congestion
- 2014
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- The need to more precisely represent the consequences of congestion mitigation policies in urban transport systems calls for replacement of the static equilibrium assignment by DTA in the integrated travel demand and traffic assignment models. Despite of the availability of DTA models and despite of the conceptual clarity of how such integration should take place, only few operational model systems have been developed for large-scale applications. We report on replacement of the static traffic assignment by two different DTAs in the four stage demand model for the Greater Stockholm region: the macroscopic analytic Visum DUE and microscopic simulation Transmodeler. First results show that even without systematic calibration the DTA is in reasonable agreement with observed traffic counts and travel times. The presented experiments did not reveal striking difference between using macroscopic and microscopic assignment package. However, given the clear trend to microscopic modeling and simulation on the travel demand side, the use of micro-simulation-based DTA package appears more natural from system integration perspective.
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| 2. |
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| 3. |
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| 4. |
- Almström, Peter, et al.
(författare)
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The impact of travel costs and economic growth on cost-benefit analysis rankings
- 2012
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- The use of Cost-benefit analysis (CBA) as a tool for selecting transport investments is often questioned. It is not unusual that politicians or others in the public debate argue that the outcome of a CBA completely rely on assumptions concerning a particular input factor, such as valuation of CO2 emissions or future fuel price. This paper explores whether the relative ranking of CBA outcomes are robust with respect to some key inputs in transport demand analysis driving cost, public transport fare and economic growth. We study six different infrastructure objects (three road and three rail objects) and four alternative assumptions on input factors compared to a reference scenario.The findings suggest that single input factors in a CBA, individually have a small impact on the ranking of the studied investments. In our model calculations we observe no change in rank between a road and a rail object.
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| 5. |
- Almström, Peter, 1980-
(författare)
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Three essays on transport CBA uncertainty
- 2015
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Cost Benefit Analysis (CBA) has for a long time been used in transport planning, but it is often questioned. One main argument against CBA is that the results depend largely on assumptions regarding one or a few input factors, as for example the future fuel price or valuation of CO2 emissions.The three papers included in this thesis investigate some aspects of uncertainty in transport CBA calculations. The two first papers explore how changes in input data assumptions affect the CBA ranking of six rail and road investments in Stockholm. The first paper deals with the effect of different land-use assumptions while the second deals with the influence of economic growth, driving cost and public transport fare. The third paper investigates how alternative formulations of the public transport mode choice and route choice affect travel flows, ticket revenues and consumer surplus. These are important factors previously known to affect CBA results.The findings of the first two papers suggest that CBA results are robust concerning different land-use scenarios and single input factors. No change in rank between a road and a rail object is observed in the performed model calculations, and only one change between two road objects. The fact that CBA results seem robust regarding input assumptions supports the use CBA as a tool for selecting transport investments. The results in the third paper indicate that if there is detailed interest in, for example, number of boardings and ticket income from a certain transit line, or the total benefit of a price change, a more detailed formulation of the public transport mode choice and route choice will provide more reliable results. On the other hand, this formulation requires substantially more data on the transit line and price structure than the conventional formulation used in Swedish transport planning, especially in areas with many different pricing systems.
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| 6. |
- Anderstig, Christer, et al.
(författare)
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Congestion Charges and Labour Market Imperfections
- 2016
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Ingår i: Journal of Transport Economics and Policy. - : UNIV BATH. - 0022-5258 .- 1754-5951. ; 50, s. 113-131
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Tidskriftsartikel (refereegranskat)abstract
- Standard cost-benefit analyses of transport policy measures will not capture all benefits and losses if there are labour market imperfections. In the case of congestion charges, theoretical analyses have raised concerns that these effects may constitute considerable losses, possibly to the extent that aggregate welfare is reduced, contrary to conventional wisdom. We investigate this by estimating the effects on labour income of the Stockholm congestion charges, using an estimated relationship between accessibility and income. Results show that effects on labour income are, in fact, positive. It turns out to be crucial that the model accounts for value-of-time heterogeneity.
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| 7. |
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| 8. |
- Anderstig, Christer, et al.
(författare)
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Congestion charges and labour market imperfections : “wider economic benefits” or “losses”?
- 2012
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- The presence of distortive taxation and agglomeration benefits in the labour market means that there are benefits and losses not captured by standard cost-benefit analyses of transport policy measures. Recent theoretical analyses have raised concerns that the labour market effects of congestion charges may constitute considerable losses in the form of reduced aggregate labour income, over and above what is captured by the consumer surplus in the standard analysis of congestion charges – possibly to the extent that congestion charges may reduce aggregate social welfare, contrary to conventional wisdom in transport economics. The sign and size of these effects are an empirical question, however. We investigate this issue by estimating the labour income effects of the Stockholm congestion charges, using an estimated relationship between workplace accessibility and labour income. Results show positive effects on labour income, meaning that the “wider economic benefits” of this system are in fact benefits, not losses. It turns out to be crucial that the model accounts for value-of-time heterogeneity in the income/accessibility relationship and in the calculation of generalized travel costs.
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| 10. |
- Berglund, Anders, 1970-, et al.
(författare)
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The GIFI approach to non-linear PLS modeling
- 2001
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Ingår i: Journal of Chemometrics. - : Wiley Inter Science. - 0886-9383 .- 1099-128X. ; 15:4, s. 321-36
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Tidskriftsartikel (refereegranskat)abstract
- The GIFI approach to non-linear modeling involves the transformation of quantitative variables to a set of 1/0 dummies in a similar manner to the way qualitative variables are coded. This is followed by analyzing the sets of 1/0 dummies by principal component analysis, multiple regression or, as discussed here, PLS. The patterns of the resulting coefficients indicate the nature of the non-linearities in the data. Here the potential uses and limitations of PLS regression, in combination with four variants of GIFI coding, are investigated using both simulated and empirical data sets.
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