Skip to main content
Log in

Assessing the Demand Vulnerability of Equilibrium Traffic Networks via Network Aggregation

  • Published:
Networks and Spatial Economics Aims and scope Submit manuscript

Abstract

Studies of network vulnerability mostly focus on changes to the supply side; whether considering a degradation of link capacity or complete link failure. However, the level of service provided by a transport network is also vulnerable to increases in travel demand, with the consequent congestion causing additional delays. Traffic equilibrium models can be used to evaluate the influence of travel demand on level of service when interest is restricted to only a small number of pre-specified demand scenarios. A demand-vulnerability analysis requires understanding the impact of unknown future changes to any possible combination of OD demands. For anything but the smallest networks, this cannot be accomplished by re-computing network equilibrium at all possible demand settings. We require a representation of the functional relationship between demands and levels of service, avoiding the need to re-evaluate the equilibrium model. This process—of collapsing the demand and network representations onto a single, coarse-level network with explicit functional relationships—is referred to here as ‘network aggregation’. We present an efficient method for network aggregation for networks operating under Stochastic User Equilibrium (SUE). In numerical experiments, we explore the nature and extent of the aggregation errors that may arise.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Fig. 1
Fig. 2
Fig. 3
Fig. 4
Fig. 5
Fig. 6
Fig. 7
Fig. 8
Fig. 9
Fig. 10
Fig. 11
Fig. 12
Fig. 13
Fig. 14
Fig. 15
Fig. 16
Fig. 17
Fig. 18
Fig. 19

Similar content being viewed by others

Notes

  1. Our classification covers only those approaches which begin with a discrete graph representation and aim for some kind of simplified representation from that graph. Hence, although they have some relation, we exclude from this classification continuum models, whereby a dense urban network is represented as a continuum, with flows comprising a vector field (e.g. Dafermos 1980; Wong 1998; Daniele, Idone and Maugeri 2003).

  2. Indeed the equilibrium link flows and costs themselves cannot typically be expressed as explicit functions of the network parameters and OD demands.

  3. While a map is provided on Bar-Gera’s website the map node numbers do not match the data file(s) and hence it cannot be used to identify ODs.

References

  • Ardekani S, Herman R (1987) Urban network-wide traffic variables and their relations. Transp Sci 21(1):1–16

    Article  Google Scholar 

  • Batty M, Sikdar PK (1982a) Spatial aggregation in gravity models: 1. An information-theoretic framework. Environ Plan A 14(3):377–405

    Article  Google Scholar 

  • Batty M, Sikdar PK (1982b) Spatial aggregation in gravity models: 2. One-dimensional population density models. Environ Plan A 14(4):525–553

    Article  Google Scholar 

  • Batty M, Sikdar PK (1982c) Spatial aggregation in gravity models: 3. Two-dimensional trip distribution and location models. Environ Plan A 14(5):629–658

    Article  Google Scholar 

  • Batty M, Sikdar PK (1982d) Spatial aggregation in gravity models: 4. Generalizations and large-scale applications. Environ Plan A 14(6):795–822

    Article  Google Scholar 

  • Bell MGH, Iida Y (1997) Transportation network analysis. Wiley, Chichester

    Book  Google Scholar 

  • Bell MGH (2000) A game theory approach to measuring the performance reliability of transport networks. Transportation Research Part B: Methodological 34(6):533–545

  • Berdica K (2002) An introduction to road vulnerability: what has been done, is done and should be done. Transp Policy 9:117–127

    Article  Google Scholar 

  • Bouthelier F, Daganzo CF (1979) Aggregation with multinomial probit and estimation of disaggregate models with aggregate data—a new methodological approach. Transp Res B Methodol 13(2):133–146

    Article  Google Scholar 

  • Bovy PHL, Jansen GRM (1983) Network aggregation effects upon equilibrium assignment outcomes: an empirical investigation. Transp Sci 17(3):240–262

    Article  Google Scholar 

  • Boyles SD (2012) Bush-based sensitivity analysis for approximating subnetwork diversion. Transp Res B Methodol 46(1):139–155

    Article  Google Scholar 

  • Cantarella GE (1997) A general fixed-point approach to multimode multi-user equilibrium assignment with elastic demand. Transp Sci 31(2):107–128

    Article  Google Scholar 

  • Chan Y (1976) Method to simplify network representation in transportation-planning. Transp Res 10(3):179–191

    Article  Google Scholar 

  • Chang KT, Khatib Z, Ou YM (2002) Effects of zoning structure and network detail on traffic demand modeling. Environ Plan B-Plan Des 29(1):37–52

    Article  Google Scholar 

  • Chen A, Yang H, Lo HK, Tang WH (2002) Capacity reliability of a road network: an assessment methodology and numerical results. Transp Res 36B(3):225–252

    Article  Google Scholar 

  • Chen BY, Lam WHK, Sumalee A, Li Q, Li Z-C (2012) Vulnerability analysis for large-scale and congested road networks with demand uncertainty. Transp Res A 46:501–516

    Google Scholar 

  • Clark SD, Watling DP (2002) Sensitivity analysis of the probit-based stochastic user equilibrium assignment model. Transp Res B 36(7):617–635

    Article  Google Scholar 

  • Connors RD, Sumalee A, Watling DP (2007) Sensitivity analysis of the variable demand probit stochastic user equilibrium with multiple user-classes. Transp Res B Methodol 41(6):593–615

    Article  Google Scholar 

  • D’Este GM, Taylor MAP (2001) Modelling network vulnerability at the level of national strategic transport network. J East Asia Soc Transp Stud 4(2):1–14

    Google Scholar 

  • Dafermos S (1980) Continuum modeling of transportation networks. Transp Res B Methodol 14(3):295–301

    Article  Google Scholar 

  • Daganzo CF (1980a) An equilibrium algorithm for the spatial aggregation problem of traffic assignment. Transp Res B Methodol 14(3):221–228

    Article  Google Scholar 

  • Daganzo CF (1980b) Network representation, continuum approximations and a solution to the spatial aggregation problem of traffic assignment. Transp Res B Methodol 14(3):229–239

    Article  Google Scholar 

  • Daganzo CF (2007) Urban gridlock: macroscopic modeling and mitigation approaches. Transp Res B Methodol 41(1):49–62

    Article  Google Scholar 

  • Daganzo CF, Geroliminis N (2008) An analytical approximation for the macroscopic fundamental diagram of urban traffic. Transp Res B Methodol 42(9):771–781

    Article  Google Scholar 

  • Daniele P, Idone G, Maugeri A (2003) The continuum model of transportation problem. Daniele P, Giannessi F, and Maugeri A (eds)

  • Davis G (1994) Exact local solution of the continuous network design problem via stochastic user equilibrium assignment. Transp Res B Methodol 28(1):61–75

    Article  Google Scholar 

  • Friesz T (1985) Transportation network equilibrium, design and aggregation—key developments and research opportunities. Transp Res Policy Pract 19(5–6):413–427

    Google Scholar 

  • Hearn DW (1984) Practical and theoretical aspects of aggregation problems in transportation planning methods. In: Florian M (ed) Transportation planning models. North-Holland, Amsterdam, pp 257–287

    Google Scholar 

  • Herman R, Prigogine I (1979) A two-fluid approach to town traffic. Science 204(4389):148–151

    Article  Google Scholar 

  • Hills PJ (2001) Supply curves for urban road networks—a comment. J Transp Econ Policy 35:343–348

    Google Scholar 

  • Ho HW, Sumalee A, Lam WHK, Szeto WY (2013) A continuum modelling approach for network vulnerability analysis at regional scale. Pap ISTTTProcedia Soc Behav Sci 80:846–859

    Article  Google Scholar 

  • Jenelius E, Petersen T, Mattsson L-G (2006) Importance and exposure in road network vulnerability analysis. Transp Res A 40:537–560

    Google Scholar 

  • Knoop VL, Snelder M, Van Zuylen HJ, Hoogendoorn SP (2012) Link-level vulnerability indicators for real-world networks. Transp Res A 46:843–854

    Google Scholar 

  • Lam WHK, Shao H, Sumalee A (2008) Modeling impacts of adverse weather conditions on a road network with uncertainty in demand and supply. Transp Res A 42(10):890–910

    Article  Google Scholar 

  • Lighthill M, Whitham G (1955) On kinematic waves.2. A theory of traffic flow on long crowded roads. Proc R Soc Lond Ser Math Phys Sci 229(1178):317–345

    Article  Google Scholar 

  • May AD, Shepherd SP, Bates JJ (2000) Supply curves for urban road networks. J Transp Econ Policy 34:261–290

    Google Scholar 

  • May AD, Shepherd SP, Bates JJ (2001) Supply curves for urban road networks—a rejoinder. J Transp Econ Policy 35:349–352

    Google Scholar 

  • Nakayama S, Watling DP (2014) Consistent formulation of network equilibrium with stochastic flows. Trans Res B

  • Nicholson AJ, Dalziell E (2003) Risk evaluation and management: a road network reliability study. In: Iida B (ed) ‘The network reliability of transport’. Pergamon-Elsevier, Oxford, pp 45–59

    Chapter  Google Scholar 

  • Openshaw S (1977) Optimal zoning systems for spatial interaction models. Environ Plan A 9(2):169–184

    Article  Google Scholar 

  • Patriksson M (2004) Sensitivity analysis of traffic equilibria. Transp Sci 38(3):258–281

    Article  Google Scholar 

  • Rogers DF, Plante RD, Wong RT et al (1991) Aggregation and disaggregation techniques and methodology in optimization. Oper Res 39(4):553–582

    Article  Google Scholar 

  • Sbayti H, El-Fadel M, Kaysi I (2002) Effect of roadway network aggregation levels on modeling of traffic-induced emission inventories in Beirut. Transp Res Part D: Transp Environ 7(3):163–173

    Article  Google Scholar 

  • Shao H, Lam WHK, Tam ML (2006) A reliability-based stochastic traffic assignment model for network with multiple user classes under uncertainty in demand. Netw Spat Econ 6:173–204

    Article  Google Scholar 

  • Sheffi Y (1984) Aggregation and equilibrium with multinomial logit-models. Appl Math Model 8(2):121–127

    Article  Google Scholar 

  • Sheffi Y (1985) Urban transportation networks. Prentice-Hall, Englewood Cliffs

    Google Scholar 

  • Smith MJ (1979) The existence, uniqueness and stability of traffic equilibria. Transp Res B Methodol 13(4):295–304

    Article  Google Scholar 

  • Sullivan JL, Novak DC, Aultman-Hall L, Scott DM (2010) Identifying critical road segments and measuring system-wide robustness in transportation networks with isolating links: a link-based capacity-reduction approach. Transp Res A 44:323–336

    Google Scholar 

  • Sumalee A (2004) Optimal road user charging cordon design: a heuristic optimization approach. Comput Aided Civ Infrastruct Eng 19(5):377–392

    Article  Google Scholar 

  • Sumalee A, Watling DP (2008) Partition-based algorithm for estimating transportation network reliability with dependent link failures. J Adv Transp 42(3):213–238

    Article  Google Scholar 

  • Sumalee A, Uchida K, Lam WHK (2011) Stochastic multi-modal transport network under demand uncertainties and adverse weather condition. Transp Res C 19(2):338–350

    Article  Google Scholar 

  • Szeto WY, O’Brien L, O’Mahony M (2006) Risk-averse traffic assignment with elastic demands: NCP formulation and solution method for assessing performance reliability. Netw Spat Econ 6:313–332

    Article  Google Scholar 

  • Taylor MAP, Somenahalli VCS, D’Este GM (2006) Application of accessibility based methods for vulnerability analysis of strategic road networks. Netw Spat Econ 6:267–291

    Article  Google Scholar 

  • Theil H (1957) Linear aggregation in input–output analysis. Econometrica 25(1):111

    Article  Google Scholar 

  • Tsekeris T, Geroliminis N (2013) City size, network structure and traffic congestion. J Urban Econ 76:1–14

    Article  Google Scholar 

  • Uchida K (2014) Estimating the value of travel time and of travel time reliability in road networks. Transp Res B. doi:10.1016/j.trb.2014.01.002

    Google Scholar 

  • Viegas JM, Martinez LM, Silva EA (2009) Effects of the modifiable areal unit problem on the delineation of traffic analysis zones. Environ Plan B-Plan Des 36(4):625–643

    Article  Google Scholar 

  • Wardrop JG (1952) Road paper. Some theoretical aspects of road traffic research. ICE Proc Eng Div 1(3):325–362

    Article  Google Scholar 

  • Watling DP, Balijepalli NC (2012) A method to assess demand growth vulnerability of travel times on road network links. Transp Res A 46:772–789

    Google Scholar 

  • Wong SC (1998) Multi-commodity traffic assignment by continuum approximation of network flow with variable demand. Transp Res B Methodol 32(8):567–581

    Article  Google Scholar 

  • Wright I, Xiang Y, Waller L et al. (2010) The practical benefits of the Saturn Origin-based assignment algorithm and network aggregation techniques. In: Available from: http://trid.trb.org/view.aspx?id=1118347 (accessed 21 August 2013)

  • Xie F, Levinson D (2007) Measuring the structure of road networks. Geogr Anal 39(3):336–356

    Article  Google Scholar 

  • Xu Z, Sui DZ (2007) Small-world characteristics on transportation networks: a perspective from network autocorrelation. J Geogr Syst 9(2):189–205

    Article  Google Scholar 

  • Yang L, Qian D (2012) Vulnerability analysis of road networks. J Transp Syst Eng Inf Technol 12(1):105–110

    Google Scholar 

  • Yang H, Lo HK, Tang WG (2000) Travel time versus capacity reliability of a road network. In: Bell MGH, Cassir C (eds) Reliability of transport networks. Research Studies, Baldock, pp 119–138

    Google Scholar 

  • Zipkin PH (1980) Bounds for aggregating nodes in network problems. Math Program 19(1):155–177

    Article  Google Scholar 

Download references

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to Richard D. Connors.

Appendix: Toy City Link Cost Function Parameters

Appendix: Toy City Link Cost Function Parameters

$$ t(x)= ff+ B{\left(\frac{x}{C}\right)}^{\beta} $$
Table 3 Link Cost Function Parameters for Toy City Network

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Connors, R.D., Watling, D.P. Assessing the Demand Vulnerability of Equilibrium Traffic Networks via Network Aggregation. Netw Spat Econ 15, 367–395 (2015). https://doi.org/10.1007/s11067-014-9251-9

Download citation

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s11067-014-9251-9

Keywords

Navigation