Analyzing the severity of bicycle-motor vehicle collision using spatial mixed logit models: A City of Edmonton case study

Implications of Competitor Representation on Optimal Design

Volume 2A: 45th Design Automation Conference ◽

10.1115/detc2019-98114 ◽

2019 ◽

Author(s):

Arthur H. C. Yip ◽

Jeremy J. Michalek ◽

Kate S. Whitefoot

Keyword(s):

Optimal Design ◽

Latent Class ◽

Mixed Logit ◽

Profit Maximization ◽

Large Set ◽

Logit Models ◽

Product Representation ◽

Mixed Logit Models ◽

The Cost

Abstract We investigate the effect of competitor product representation on optimal design results in profit-maximization studies. Specifically, we study the implications of replacing a large set of product alternatives available in the marketplace with a reduced set of selected competitors or with composite alternatives, as is common in the literature. We derive first-order optimality conditions and show that optimal design (but not price) is independent of competitors under the logit and nested logit models (where preference coefficients are homogeneous), but optimal design results may depend on competitor representation in latent class and mixed logit models (where preference coefficients are heterogeneous). In a case study of automotive powertrain design using mixed logit demand, we find some change in the optimal acceleration performance value when competitors are modeled using a small set of alternatives rather than the larger set. The magnitude of this change depends on the specific form and parameters of the cost and demand functions assumed, ranging from 0% to 3% in our case study. We find that the magnitude of the change in optimal design variables induced by competitor representation in our case study increases with the heterogeneity of preference coefficients across consumers and changes with the curvature of the cost function.

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Modeling Travel Mode Choices in Connection to Metro Stations by Mixed Logit Models: A Case Study in Nanjing, China

PROMET - Traffic&Transportation ◽

10.7307/ptt.v30i5.2623 ◽

2018 ◽

Vol 30 (5) ◽

pp. 549-561 ◽

Cited By ~ 2

Author(s):

Jingxian Wu ◽

Min Yang ◽

Shangjue Sun ◽

Jingyao Zhao

Keyword(s):

Mixed Logit ◽

Urban Rail Transit ◽

Policy Implications ◽

Rail Transit ◽

Logit Models ◽

Mixed Logit Models ◽

Urban Rail ◽

Temporally Correlated ◽

Electric Bike

Urban rail transit trips usually involve multiple stages, which can be differentiated in terms of transfers that may involve distinct access and egress modes. Most studies on access and egress mode choices of urban rail transit have separately examined the two mode choices. However, in reality, the two choices are temporally correlated. This study, therefore, has sequentially applied the mixed logit to examine the contributors of access and egress mode choices of urban metro commuters using the data from a recent survey conducted in Nanjing, China. 9 typical multimodal combinations constituted by 5 main access modes (walk, bike, electric bike, bus, and car) and 2 main egress modes (walk and bus) are included in the study. The result proves that the model is reliable and reproductive in analyzing access/egress mode choices of metro commuters. Estimation results prove the existence of time constraint and service satisfaction effect of access trip on commuters’ egress mode choice and reveal the importance of transfer infrastructure and environments that serve for biking, walking, bus riding, and car parking in commuter’s connection choice. Also, policy implications are segmentally concluded for the transfer needs of commuters in different groups to encourage the use of metro multimodal trips.

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