| 1. |
- Hassler, John, et al.
(författare)
-
Svensk politik för globalt klimat
- 2020
-
Bok (övrigt vetenskapligt/konstnärligt)abstract
- Nio forskare från olika discipliner ingår i SNS Konjunkturråd 2020. Forskarna har bred bakgrund inom nationalekonomi, juridik, naturvetenskap och ingenjörsvetenskap. Tillsammans har de skrivit SNS Konjunkturrådsrapport 2020: Svensk politik för globalt klimat, där de fokuserar på hur politiken ska utformas för att bromsa och till slut stoppa klimatförändringarna. Några av deras viktigaste förslag och rekommendationer: Låt kolet stanna i marken. Det är kolet, inte konventionell olja, som är det centrala hotet mot klimatet. Om klimatförändringarna ska hejdas måste Kina bli av med sitt kolberoende. Indien och Afrika kan inte heller följa Kinas kolkraftsbaserade utvecklingsstrategi. Merparten av världens kolreserver måste stanna i marken.Inför globalt minimipris på koldioxidutsläpp och slopa fossilsubventioner. Det är två nödvändiga ingredienser i klimatpolitiken som måste diskuteras på FN:s nästa stora klimatkonferens COP26 i Glasgow.Gröna subventioner räcker inte för att minska utsläppen. Billig grön energi leder till ökad användning av sådan men inte automatiskt till att fossila bränslen utkonkurreras.Bidra till rätt global inriktning. Den svenska klimatpolitiken bör ha som överordnat mål att minska de globala utsläppen.Bidra finansiellt till andra länders omställning. Klokt och välavvägt klimatbistånd är både möjligt och önskvärt. Inom ramen för EU:s klimatpolitik finns fungerande sätt att finansera mindre rika medlemsländers utsläppsminskningar. Men eftersom även Sverige måste bli klimatneutralt bör ett ökat klimatbistånd inte minska de svenska klimatambitionerna.Klimatklubbar. Sverige bör driva frågan om att det ska vara tillåtet att införa klimattullar mot länder som inte har en acceptabel nivå på utsläppspriset. En modell är så kallade klimatklubbar där länder går ihop och sätter ett enhetligt utsläppspris. Import från länder som inte deltar i klubben beläggs med en tull.Fossilfri elexport kan ge betydande minskningar av utsläppen inom EU genom att pressa undan kolkraft där sådan fortfarande används.Finansiera insamling och lagring av koldioxid (CCS-teknik) med lagringspeng. Vi kan ta hand om koldioxid motsvarande hälften av Sveriges utsläpp till en kostnad motsvarande det som dras in till staten via koldioxidskatten. Det krävs dock en statlig finansiering som bör utformas som ett bidrag per ton insamlad och säkert lagrad koldioxid:– Motsvarande runt hälften av Sveriges koldioxidutsläpp kan tas bort om CCS-tekniken införs på de 27 industrianläggningar som släpper ut mest i Sverige. Detta är mer än utsläppen från hela den svenska vägtrafiken. Tekniken fungerar också i resten av världen och Sverige kan här bli ett föregångsland, säger John Hassler, ordförande i SNS Konjunkturråd 2020.
|
|
| 2. |
- Ait-Ali, Abderrahman, 1991-, et al.
(författare)
-
Are commuter train timetables consistent with passengers’ valuations of waiting times and in-vehicle crowding?
- 2020
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Many models have been developed and used to analyse the costs and benefits of transport investments. Similar tools can also be used for transport operation planning and capacity allocation. An example of such use is the assessment of commuter train operations and service frequency. In this study, we analyse the societally optimal frequency for commuter train services. The aim is to reveal the implicit valuation (by the public transport agency) of the waiting time and the in-vehicle crowding in the commuting system. We use an analytic CBA model to formulate the societal costs of a certain service frequency and analyse the societally optimal frequencies during peak and off-peak hours. Comparing the optimal and the actual frequencies allows to reveal the implicit valuations of waiting time and crowding. Using relevant data from the commuter train services in Stockholm on a typical working day in September 2015 (e.g., OD matrix, cost parameters), we perform a numerical analysis on certain lines and directions. We find the societally optimal frequency and the implicit valuation of waiting time and crowding. The results suggest that the public transport agency in Stockholm (i.e., SL) adopted service frequencies that are generally slightly higher than societally optimum which can be explained by a higher implicit valuation of waiting time and crowding. We also find that the optimal frequencies are more sensitive to the waiting time valuation rather than that of crowding.
|
|
| 3. |
- Ait Ali, Abderrahman, 1991-, et al.
(författare)
-
Are commuter train timetables consistent with passengers’ valuations of waiting times and in-vehicle crowding?
- 2022
-
Ingår i: Transport Policy. - : Elsevier BV. - 0967-070X .- 1879-310X. ; 116, s. 188-198
-
Tidskriftsartikel (refereegranskat)abstract
- Social cost-benefit analysis is often used to analyse transport investments, and can also be used for transport operation planning and capacity allocation. If it is to be used for resolving capacity conflicts, however, it is important to know whether transit agencies' timetable requests are consistent with the cost-benefit framework, which is based on passenger preferences. We show how a public transport agency's implicit valuations of waiting time and crowding can be estimated by analysing timetables, apply the method to commuter train timetables in Stockholm, and compare the implicit valuations to the corresponding passenger valuations in the official Swedish cost-benefit analysis guidelines. The results suggest that the agency puts a slightly lower value on waiting time and crowding than the passenger valuations codified in the official guidelines. We discuss possible reasons for this and implications for using cost-benefit analysis for capacity allocation. We also find that optimal frequencies are more sensitive to the waiting time valuation than to that of crowding.
|
|
| 4. |
- Ait Ali, Abderrahman, 1991-, et al.
(författare)
-
European Railway Deregulation : An overview of market organization and capacity allocation
- 2022
-
Ingår i: Transportmetrica A. - : Taylor & Francis. - 2324-9935 .- 2324-9943. ; 18:3, s. 594-618
-
Tidskriftsartikel (refereegranskat)abstract
- Railway markets in Europe have been reorganized to allow competition between different operators. Thus, European railways have been vertically separated, separating infrastructure management from provisions of train services. This allows several train operators to compete for passengers and freight services. Different ways have emerged for vertical separation, capacity allocation and track access charges. This paper reviews, compares and discusses important deregulation aspects, using examples from a number of European countries to show different possible solutions. The study describes how competition has been introduced and regulated, with a particular focus on describing the different ways capacity is allocated and how conflicting requests by different train operators are resolved. It also reviews the related issue of how access charges are constructed and applied. Although guided by the same European legislation, we conclude that the studied railways have different deregulation outcomes, e.g., market organization, capacity allocation. Besides, few countries have so far managed to create efficient and transparent processes for allocating capacity between competing train operators. Although allowed by the legislation, market-based allocation is absent or never used. In order to foster more competition which can yield substantial social benefits, the survey indicates that most European railways still need to develop and experiment with more efficient and transparent capacity allocation procedures.
|
|
| 5. |
- Ait Ali, Abderrahman, 1991-, et al.
(författare)
-
Measuring the Socio-economic Benefits of Train Timetables : Application to Commuter Train Services in Stockholm
- 2017
-
Ingår i: 20th EURO Working Group on Transportation Meeting, EWGT 2017, 4-6 September 2017, Budapest, Hungary. - : Elsevier. ; , s. 849-856
-
Konferensbidrag (refereegranskat)abstract
- On highly used railway lines with heterogeneous traffic, timetabling is challenging. In particular, the limited existing capacity means that to guarantee an acceptable level of quality, the infrastructure manager must cancel some train services on the expense of others. In this article, we study the conflict between commercial long-distance trains and subsidized commuter trains with a socio-economic perspective (i.e. travelers and train operators). The study attempts to answer the following question: What is the socio-economic effect of modifying the timetable of a commuter service?The case study treats the commuter train services in Stockholm. Trip data was collected from the local commuter train operator. An entropy maximization-based model was implemented to estimate the dynamic network Origin-Destination (OD) matrix. This dynamic matrix, of one full working day, was then used to estimate the number of travelers per train, and further converted for use in the microscopic simulation tool RailSys. Travel and waiting time are estimated for each OD pair and with that the generalized costs for the travelers and operators. The effect of crowding in the trains is included in the estimation. The article can be considered as an initiation to a novel method to calculate effects of changes in commuter train timetables. This novel approach enables to price commercial train slots in the capacity allocation process such as in an auction. It provides a new way to estimate the local train operator´s valuation of the different parameters (i.e. waiting, travel time and interchanges). Using RailSys for the estimation of times makes it possible to include capacity aspects that normally are difficult to reveal.
|
|
| 6. |
- Ait-Ali, Abderrahman, 1991-, et al.
(författare)
-
Pricing commercial train path requests based on societal costs
- 2019
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- On deregulated railway markets, efficient capacity allocation is important. We study the case where commercial trains and publicly controlled traffic (“commuter trains”) use the same railway infrastructure and hence compete for capacity. We develop a method that can be used by an infrastructure manager trying to allocate capacity in a socially efficient way. The method calculates the loss of social benefits incurred by changing the commuter train timetable to accommodate a commercial train path request and based on this calculates a reservation price for the train path request. If the commercial operator’s willingness-to-pay for the train path exceeds the loss of social benefits, its request is approved. The calculation of social benefits takes into account changes in commuter train passengers’ travel times, waiting times, transfers and crowding, and changes in operating costs for the commuter train operator(s). The method is implemented in a microscopic simulation program, which makes it possible to test the robustness and feasibility of timetable alternatives. We show that the method is possible to apply in practice by demonstrating it in a case study from Stockholm, illustrating the magnitudes of the resulting commercial train path prices. We conclude that marginal societal costs of railway capacity in Stockholm are considerably higher than the current track access charges.
|
|
| 7. |
- Ait-Ali, Abderrahman, 1991-, et al.
(författare)
-
Railway capacity allocation : a survey of market organizations, allocation processes and track access charges
- 2019
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- In the last few decades, many railway markets (especially in Europe) have been restructured to allow competition between different operators. This survey studies how competition has been introduced and regulated in a number of different countries around the world. In particular, we focus on a central part of market regulation specific to railway markets, namely the capacity allocation process. Conflicting capacity requests from different train operators need to be regulated and resolved, and the efficiency and transparency of this process is crucial. Related to this issue is how access charges are constructed and applied. Several European countries have vertically separated their railway markets, separating infrastructure management from train services provisions, thus allowing several train operators to compete with different passengers and freight services. However, few countries have so far managed to create efficient and transparent processes for allocating capacity between competing train operators, and incumbent operators still have larger market-share in many markets.
|
|
| 8. |
- Ait-Ali, Abderrahman, 1991-, et al.
(författare)
-
The value of additional data for public transport origin-destination matrix estimation
- 2022
-
Ingår i: Public Transport. - : Springer Science+Business Media B.V.. - 1866-749X .- 1613-7159. ; 14:2, s. 419-439
-
Tidskriftsartikel (refereegranskat)abstract
- Passenger origin–destination data is an important input for public transport planning. In recent years, new data sources have become increasingly common through the use of the automatic collection of entry counts, exit counts and link flows. However, collecting such data can be sometimes costly. The value of additional data collection hence has to be weighed against its costs. We study the value of additional data for estimating time-dependent origin–destination matrices, using a case study from the London Piccadilly underground line. Our focus is on how the precision of the estimated matrix increases when additional data on link flow, destination count and/or average travel distance is added, starting from origin counts only. We concentrate on the precision of the most policy-relevant estimation outputs, namely, link flows and station exit flows. Our results suggest that link flows are harder to estimate than exit flows, and only using entry and exit data is far from enough to estimate link flows with any precision. Information about the average trip distance adds greatly to the estimation precision. The marginal value of additional destination counts decreases only slowly, so a relatively large number of exit station measurement points seem warranted. Link flow data for a subset of links hardly add to the precision, especially if other data have already been added.
|
|
| 9. |
- Ait Ali, Abderrahman, 1991-, et al.
(författare)
-
The value of additional data for public transport origin–destination matrix estimation
- 2022
-
Ingår i: Public Transport. - : Springer. - 1866-749X .- 1613-7159. ; 14:2, s. 419-439
-
Tidskriftsartikel (refereegranskat)abstract
- Passenger origin–destination data is an important input for public transport planning. In recent years, new data sources have become increasingly common through the use of the automatic collection of entry counts, exit counts and link flows. However, collecting such data can be sometimes costly. The value of additional data collection hence has to be weighed against its costs. We study the value of additional data for estimating time-dependent origin–destination matrices, using a case study from the London Piccadilly underground line. Our focus is on how the precision of the estimated matrix increases when additional data on link flow, destination count and/or average travel distance is added, starting from origin counts only. We concentrate on the precision of the most policy-relevant estimation outputs, namely, link flows and station exit flows. Our results suggest that link flows are harder to estimate than exit flows, and only using entry and exit data is far from enough to estimate link flows with any precision. Information about the average trip distance adds greatly to the estimation precision. The marginal value of additional destination counts decreases only slowly, so a relatively large number of exit station measurement points seem warranted. Link flow data for a subset of links hardly add to the precision, especially if other data have already been added.
|
|
| 10. |
|
|
