Behavioral insights in route choice models with real-time information Eran Ben-Elia1, Yoram Shiftan2* & Ido Erev3 1 Mr. Eran Ben-Elia, Ph.D Student, Faculty of Civil & Environmental Engineering, Technion - Israel Institute of Technology, Technion City, Haifa, 32000, Israel. 2* Dr. Yoram Shiftan, Associate Professor, Faculty of Civil & Environmental Engineering, Technion - Israel Institute of Technology, Technion City ,Haifa, 32000, Israel. 3 Dr. Ido Erev, Professor, Faculty of Industrial Engineering & Management, Technion Israel Institute of Technology, Technion City ,Haifa, 32000, Israel. (* author for correspondence: shiftan@technion.ac.il) Behavioral insights in route choice models with real-time information Eran Ben-Elia, Yoram Shiftan & Ido Erev Abstract This paper deals with the behavioral aspects of drivers’ decision making processes when faced with Advanced Travel Information Systems (ATIS). Route-choice models can be improved with realistic behavioral assumptions. However, different choices arise when decisions are taken on the basis of information compared to those taken on the basis of experience. An experiment was designed to investigate route choices relying on a description of travel time variability and also on personal experience through feedback. The results show information has a positive effect and is more evident when participants lack experience on the distributions of travel times. Information seems to increase initial risk seeking behavior, reduce initial exploration and contribute to larger between subject risk-attitudes differences. These findings have important implications for ATIS design especially in the conditions characterized by non recurring congestion. 1 Behavioral insights in route choice models with real-time information Eran Ben-Elia, Yoram Shiftan & Ido Erev 1. Introduction Suppose a driver is faced with real-time information regarding the choice between two routes from work to home: a faster route (F) and a slower route (S). The average travel times on the faster route is predicted to be 25 minutes and on the slower one - 30 minutes. The driver has no specific obligation to arrive home on a specific time, but obviously would like to drive the least amount of time. Suppose also that the driver is provided with real time information regarding the travel time ranges (the deviation around the mean value). The ranges are 5 or 15 minutes for each route. Based on the above information we can construct three possible travel scenarios by combining travel time means and ranges (see Table 1). For the purpose of this study these scenarios are defined as: 1. Safer-Fast (faster route has a low travel time range compared to the slower route; 2. Risky-Fast (faster route has a high travel time range compared to the slower route; 3. Low-Risk (both route have equal and low travel time ranges). What would the expected proportion of choices of the fast route, referred to as P(Fast), be in each case? The problem to predict a driver’s route choice although at first glance simple is not trivial. Rational choice and decision making has been at the core of modeling travel behavior in general and route choice in particular. In route choice studies, many modeling applications consist of the wide family of discrete choice models. These include first, the classic Multinomial Logit Model (Daganzo & Sheffi, 1977) and its applications: C-logit (Cascetta et al., 1996), IAP logit (Cascetta and Papola 1998) and 2 Behavioral insights in route choice models with real-time information Eran Ben-Elia, Yoram Shiftan & Ido Erev Path-Size Logit (Ben- Akiva & Bierlaire, 1999). Second, the General Extreme Value theorem (McFadden, 1978) to whom MNL is also affiliated, and its applications: Nested logit (Ben Akiva & Lerman, 1985); Cross-Nested Logit (Vovsha, 1997), General Nested Logit (Wen and Koppelman, 2001) and Paired Combinatorial Logit (Chu, 1989). Finally, the recent and promising Mixed Logit or Logit Kernel model with flexible probit like structures (McFadden and Train, 2000; Ben-Akiva and Bolduc, 1996). In general, discrete choice models assign each alternative route a utility value which accordingly sets its choice probability usually with an exponential response rule. These models are econometrically derived from random utility theory. An individual’s utility for each route of an origin–destination pair is assumed to have a deterministic (or observable) component and a random component or error term, representing components of drivers’ disutility that are not explained through observed attributes i.e. individual perception errors, measurement errors and specification errors. Prashker & Bekhor, (2004) provide an extensive review of random utility models (RUM) and their application in route choice studies. Discrete choice models provide parsimony and econometric elegant abstraction of drivers’ behavior, but do not include explicit abstraction of the effect of the information provided by ATIS. Capturing the effect of the drivers’ information within the framework of discrete choice models requires additional behavioral assumptions. Previous attempts to address the effect of information on drivers’ behavior focus on three main approaches. The first approach, focuses on the error term in the routes’ utilities functions thus providing information implied less error in the system (e.g. Watling & Van Vuren, 1993 and see review by Bonsall, 2000). A second approach is to reduce system error by gaining more knowledge through reinforced learning. For example, Horowitz (1984) described a simple route choice model over time whereby decisions are 3 Behavioral insights in route choice models with real-time information Eran Ben-Elia, Yoram Shiftan & Ido Erev based on the weighted average of previous travel decisions’ utilities. A third approach involves direct empirical research. Recent studies attempt to model the utilities of information and information acquisition through stated preference in laboratory simulations (e.g. Abdel Aty & Abdullah, 2004; Peeta et. al., 2000; Tong, 2000; Wong-Wing Gun, 1999; Sirnivasan & Mahamassani, 1999; Abdel-Aty et. al., 1997; Mahmassani and Liu, 1998). Although similar in their approach to previous discrete choice studies (without information effects) these studies enabled perception and processing mechanisms based on principles of bounded rationality (Simon, 1982), simple heuristics and limited sets of choice rules. In addition other studies applied fuzzy logic principles like “if-then” rules (Peeta & Yu, 2005; Lotan, 1993) or dynamic assignment and micro simulation using artificial agents (Nakayama et, al., 2001; Nakayama & Kitamura, 2000; Nakayama et. al., 1999; Bonsall et. al., 1997). A few studies attempted to investigate information impacts using revealed preference field studies of real locations or ATIS systems (Fujii & Kitamura, 2000, Kraan et. al., 1999; Deakin, 1997; Wardman et.al., 1997; Khattak & Khattak., 1996). The current research is designed to contribute to this line of empirical research by building on the findings of recent behavioral research. 2. Insights from behavioral theory Returning to our driver’s predicament, three robust behavioral regularities that have been documented in basic decision research lead to contradicting predictions in our current example. In this context we refer to maximization as the tendency to maximize the potential payoff i.e. to choose more often on average the faster route 4 Behavioral insights in route choice models with real-time information Eran Ben-Elia, Yoram Shiftan & Ido Erev The ‘hot stove’ effect March and Denrell (2001, and see Denrell, in press) demonstrate that when the feedback available to the decision makers is limited to their obtained payoff, experience reduces the tendency to select risky (high variance) alternatives. Denrell and March (2001) demonstrate that this pattern, referred to as the ‘hot stove’ effect, is a natural consequence of the inherent asymmetry between the effect of good and bad experiences. In line with the ‘classic’ law of effect (Thorndike, 1898), Good outcomes are expected to increase the probability that a choice will be repeated and for that reason facilitate the collection of additional information concerning the value of the alternative that has yielded the good outcome. Bad outcomes are expected to reduce the probability that the choice will be repeated, and for that reason impair the collection of additional information concerning the value of the alternative that has yielded the bad outcome. As a result, the effect of bad outcomes is stronger (lasts longer) than the effect of good outcome, and high variability decreases the tendency to choose further the option associated with a high variability. A generalization of the ‘hot stove’ effect to the current context implies that repeated experience without ATIS is likely to lead drivers to deviate from maximization in the direction of risk aversion. Thus, ATIS is expected to increase maximization in scenario Risky-Fast, but to have little effect in the other two scenarios. Risk seeking in the loss domain In their classical paper on Prospect Theory, Kahneman and Tversky (1979) and the continuation with Cumulative Prospect Theory (Tversky & Kahneman, 1992) review the main deviation from rational choice in decisions under risk (one-shot decisions based on a complete description of the payoff distributions). One of the most important behavioral phenomena they highlight is the tendency to exhibit risk seeking in the loss 5 Behavioral insights in route choice models with real-time information Eran Ben-Elia, Yoram Shiftan & Ido Erev domain and the reverse case in the domain of gains. For example, most people prefer the gamble {lose 400$, with probability 0.8; loss nothing, otherwise} over a sure loss of 300$. A generalization of this observation to the current setting implies that the availability of ATIS (complete description of the payoff distribution) is expected to enhance deviation from maximization toward risk seeking. Thus, ATIS is expected to impair maximization in scenario Safer-Fast. A partial support to this generalization of Prospect Theory was found in the research by Katsikopoulos et. al. (2002). The authors provided participants with descriptive information about the travel time ranges of two routes while the participants drove once through various traffic scenarios on a driving simulator. They found that In the case of losses (i.e. an alternative route is on average worse off compared to a reference route) - risk seeking in route selection emerges when the alternative route is riskier )i.e. has a higher travel time range) compared to the reference route and risk averse otherwise. The payoff variability effect Experimental study of the effect of experience on human choice behavior in repeated settings reveal a robust payoff variability effect (Myers et al., 1960; Busemeyer & Townsend, 1993; and Erev & Barron, 2005). This effect results when an increase in the variance of the payoff distribution of the possible outcomes appears to move aggregate choice behavior toward random choice. Avinery and Prashker (2003) demonstrate the importance of this observation in the context of route-choice behavior. They show that increasing travel time variability of the route with a higher expected travel time increases its popularity. Since the payoff 6 Behavioral insights in route choice models with real-time information Eran Ben-Elia, Yoram Shiftan & Ido Erev variability effect is reduced by precise information (Barron & Erev, 2003) it implies that ATIS will increase maximization in all the scenarios considered here. Moreover it implies that the effect will be particularly large in Scenarios Risky-Fast and Safer-Fast. The combined effect The main goal of the current analysis is to improve our understanding of the joint effect of the three behavioral tendencies described above. In order to achieve this goal the current research examines choice behavior in an environment in which the decision makers receive partial descriptive information, and at the same time can rely also on their personal experience. This relatively new approach combines together experience and description in the decision making process which, up till now, were treated separately. A recent study by Avinery & Prashker (2006) applied this approach by providing one group of participants with a single static description of route mean values (but not of their variability) and subsequently allowing them to gain experience of their preferable route using feedback. The second group (the control), received only the latter (similar to their 2003 study). The study found that informed participants tend to prefer the safer and slower route (i.e. show risk aversion) while non informed ones prefer the risky and fast one (i.e. show the expected preference for risk seeking). This study builds on this approach whilst replacing the static information with dynamic real-time information of the ranges of travel times on available routes, consequently providing participants with a description of travel time variability as would appear on a variable message sign (VMS). We believe this will provide a more accurate representation of plausible travel time information while driving and making route choice decisions. 7 Behavioral insights in route choice models with real-time information Eran Ben-Elia, Yoram Shiftan & Ido Erev 3. Experiment design The experiment included a simple road network with two routes from work to home. One route was on average faster, with mean travel time of 25 minutes and the other slower with a mean of 30 minutes. Participants in the experiment (49 Technion students) were divided randomly between two groups – one group (N=24) received realtime information before each trial and their chosen route’s randomly drawn travel time after each choice was made (as a feedback). The other group (N=25) the control received only the feedback information but no other information regarding the possible travel times on the routes. No foregone payoff was provided. The participants’ task was to repeatedly choose between the two routes simulating commuting days. In order to encourage participants save travel time, each minute accrued in the experiment was set a cost of 0.1 NIS cents (the average payoff per participant was about 4.5$ at the time). Each group was faced with three consecutive traffic scenarios (i.e. repeated measures) as presented in Table 1 in the initial example. Each scenario was run 100 times so in total each participant provided 300 observations. The order in which the scenarios appeared was divided in to the 3! possible arrangements - in total 6 blocks. After each scenario was finished an announcement was given warning of the beginning of the next scenario. Participants were not informed in advance how many runs they were expected to complete. This reduced the possibility of routine and fatigue during the experiment. The group provided with real-time information received for each of the two routes the travel time range (the minimum and maximum travel times) as designed a priori for each scenario. This simulated a simple variable message sign (VMS). In order to allow a small variation in the provided information the mean of the travel time oscillated randomly between 0-5 (whole) minutes in respect to the initial scenario design and the 8 Behavioral insights in route choice models with real-time information Eran Ben-Elia, Yoram Shiftan & Ido Erev travel time range changed accordingly. Following the route choice the participant received as a feedback for his next choice the ‘actual’ travel time on his chosen route but not of the alternative one. The travel time was randomly drawn (using a uniform distribution) from the provided travel time range to maintain user confidence in the information. The same treatments were given to the group without information the only difference is that they did not receive the VMS message. As discussed earlier we hypothesize three, partially contradicting, behavioral tendencies: the ‘hot stove’ effect, risk seeking in the loss domain, and the payoff variability effect. 4. Results The following three figures (1,2 and 3) present the average proportions of choosing the faster route for the 100 trials in each of the three traffic scenario and for each of the two experimental conditions: with information (and with feedback) and without information (feedback only). For simplicity the data is presented in blocks of 10 trials each. For the purposes of the analysis we refer to the maximization rate as the increased propensity to choose the faster route. As expected, under all scenarios and conditions, the faster route (with the lower travel time mean) is chosen a significantly higher number of times, over the slower one. From Figures 1, 2 and 3 it is evident that participants who received no information behave more or less similarly in all of the three scenarios. The classical learning curve is obvious as it takes several trials to learn that the faster route minimizes travel times. Under Risky-Fast, learning appears slower. However, a one way ANOVA did not show significance of difference between the mean proportions of the three scenarios for the without information condition (F=1.66, p>0.05). In addition, the means and standard 9 Behavioral insights in route choice models with real-time information Eran Ben-Elia, Yoram Shiftan & Ido Erev deviations for the three scenarios without information are quite similar implying that the choice behavior appears more homogenous. As seen in the three figures above, participants who received real-time information appear to behave differently compared to those that did not receive it. However, the between group t-test was significant only for Low-Risk (t=3.17, p<0.05). Within the ‘with information’ group a one way ANOVA shows the difference between means is significant (F=3.57, p<0.05). A post hoc Duncan test shows that the mean differences between Safer-Fast and Low-Risk is significant at 0.05 while the difference between Safer-Fast and Risky-Fast is significant but only at 0.1. The difference between Risk-Fast and Low-Risk was not significant. Standard deviations are larger in the ‘with information’ group compared to the ‘without information’ one. This implies that participants receiving information are more heterogeneous in their choice behavior compared to the control group. Table 2 summarizes the results of the average maximization rates for the full data set (standard deviations are shown in parenthesis). A mixed model (with fixed and random factors) reveals that the effect of ‘Scenario’ (the repeated effect) is significant (F=7.89, p<0.05) and also the effect of the group (F=4.44, p<0.05). The effects of the order of appearance (the blocks) and the interactions are not significant. Furthermore, the estimated 33 covariance matrix showed significant results only to the variances of the choice proportions of each scenario but not of their covariance. This implies that participants treated the traffic scenarios separately as expected. At the beginning of the experiment (see Figures 1, 2 and 3 above) in all scenarios the group ‘with information’ has a higher maximization rate compared to the without 10 Behavioral insights in route choice models with real-time information Eran Ben-Elia, Yoram Shiftan & Ido Erev information group. A within group ANOVA of the first trial, representing a one shot choice based on descriptive information, shows that the difference between the means of the group ‘with information’ is significant (F=3.14, p<0.05). Under Safer-Fast, 70% choose the faster route compared to 87% under Risky-Fast. Under Low-Risk the proportion of the faster route rises to 96%. A within group ANOVA of the average choice proportions of trials 1 through 10 shows that the differences of means for the group ’with information’ are significant, while those for the group ‘without information’ are not. A post hoc Duncan test of the group ‘with information’ data shows that the mean differences between Safer Fast and RiskyFast and Safer-Fast and Low-Risk are significant. However, the mean differences between Risky-Fast and Low-Risk were not. The between group t-tests shows that under Risky-Fast and Low-Risk, the difference between group means are significant (t= 3.19, p<0.05; t=4.95, p<0.05) but not under Safer-Fast. Table 3 summarizes the results of the average maximization rates for the first 10 trials in the data set (standard deviations are shown in parenthesis). As seen in Figures 1 2 and 3, the group ‘without information’ catches up in the last 50 trials and the information effect is, to some extent replaced by an experience effect. It also appears that after 50 trials or more the group ‘with information’ has a slightly lower maximization rate (except under Low-Risk) compared to the group ‘without’. However this difference is not significant under any of the three scenarios. Table 4 summarizes the results of the average maximization rate for the last 50 trials in the data set (standard deviations are shown in parenthesis). 11 Behavioral insights in route choice models with real-time information Eran Ben-Elia, Yoram Shiftan & Ido Erev 5. Discussion The current results highlight two robust deviations from the predictions of the common application of rational choice in the context of travel behavior. First, the main behavioral tendency in decisions from experience as demonstrated in the results of the condition ‘without information’, reflect the payoff variability effect. When comparing the results of Safer-Fast to Risky-Fast - the increase in the variability of the faster route reduced the maximization rate (i.e. the proportion of the faster route) and increased the propensity to choose the slower route. This robust effect has been well documented (Avineri & Prashker ,2003; Erev & Barron, 2005) in choices situations lacking a description of the relevant payoff distributions. Second, the results for the condition ‘with information’ suggest that the initial effect of information (in the 10 initial trials) is consistent with the prediction of Prospect Theory and risk seeking in the domain of losses (Kahneman & Tversky, 1979; 1984). The fast route was more attractive when it was risky (Risky-Fast) than when it was associated with low variability (Safer-Fast). However, with longer experience behavior moves toward the predictions of the payoff variability effect. After 50 trials, the evidence for more risk seeking than risk aversion disappeared. The sole effect of variability was a reduction in the attractiveness of the faster route. An examination of the net effect of real-time information reveals an interesting pattern. As demonstrated by Avineri and Prashker (2006) in certain settings information does not increase the maximization rate. Specifically, as seen in Figure 1, in the last 50 trials, the maximization rate in the Safer-Fast scenario was lower with the availability of information (and to a lesser extent, as seen in Figure 2, also in scenario Risk-Fast). Furthermore, Avineri and Prashker (2006) stress that the negative effect of information can be explained by the claim that information increases risk aversion. The 12 Behavioral insights in route choice models with real-time information Eran Ben-Elia, Yoram Shiftan & Ido Erev comparison of our replication of the scenario run by Avineri and Prashker (2006) - RiskyFast, weakly supports this assertion. However, a comparison of scenario Safer-Fast (that did not appear in their study) with the other scenarios demonstrates that the opposite pattern is stronger. The data can be summarized with the claim that the typical effect of the information is to increase risk seeking. Moreover, in the current study the initial effect of the additional information was positive for all three scenarios. We believe that current results suggest that information has three main effects. First, reducing of initial exploration (and for that reason increases the maximization rate by inexperienced drivers). Second, increasing initial risk seeking and between-subject differences in risk attitude. The main conclusion from the analysis is that the major benefits of providing real time information with ATIS are specifically for drivers whom lack long term experience. Drivers that are new to the road network or that have limited knowledge of the travel time distributions common to it will benefit the most from the provided information. For experienced drivers whom already have a good knowledge base of the possible travel conditions on the network the effect of information is somewhat limited. It is worth noting that when traffic conditions change due to unexpected events like accidents or special events (example a large sport game) then real-time information plays a crucial role by expediting the learning process of the drivers on the network. For traffic management this has high significance since non recurring congestion (in contrary to recurring congestion) is taking an ever larger role in many urban networks (Lomax & Schrank, 2003). Frequent users and commuters can deal with recurring congestion be reinforced learning. However, better management of non recurring congestion may be possible by providing users with real time information. In these circumstances more research is 13 Behavioral insights in route choice models with real-time information Eran Ben-Elia, Yoram Shiftan & Ido Erev necessary to understand the impacts of partially informed users on the general equilibrium on the transport network. Continued research The experimental study has enabled better understanding of the two main effects taking place in the route-choice decision process – information and experience and their interaction. However an important step in designing of effective ATIS is the capability to predict driver behavior. We propose to apply the data collected during the experiment to estimate a discrete choice model (using mixed logit). The data collected includes: participants’ socio-economic characteristics (age, gender, car ownership, employment etc.), route characteristics (mean and variance of travel times), real-time information (travel time ranges on each route), feedback (chosen routes’ travel time) and route choices in the three travel scenarios described above. Using this data we can estimate a model with panel data (repeated observations for same individuals) heterogeneity (taking account of the different subject effects - random or fixed) and state dependence (currant choices depend on outcomes of previous choices). The main obstacle is to account for the decreasing importance of the descriptive information as more experience is gained over time. This can be handled with a weighting function. Acknowledgments The authors would like to thank Merav Ben-Elia (Software Engineer) for her candid assistance in developing the computer simulation program and the staff at the behavioral research laboratory and the Max Wertheimer Minerva center for Cognitive Research for assistance in carrying out the experiment. 14 Behavioral insights in route choice models with real-time information Eran Ben-Elia, Yoram Shiftan & Ido Erev References Abdel-Aty M., Abdallah M. H., (2004), Modeling drivers’ diversion from normal routes under ATIS using generalized estimating equations and binomial probit link function, Transportation, 31, 3, 327-348. Abdel-Aty M., Kitamura R., Jovanis P. (1997), Using stated preferences data for studying the effect of advanced traffic information on drivers’ route choice, Transportation Research C, 5, 1, 39-50. Avineri E., Prashker, J.N. (2003), Sensitivity to uncertainty: The need for a paradigm shift. Transportation Research Record, 1854, 90-98 Avineri E., Prashker, J.N. (2006), The impact of travel time information on travelers’ learning under uncertainty, Transportation, 33, 4, 393-408 Barron, G., Erev I., (2003), Small feedback-based decisions and their limited correspondence to description-based decisions, Journal of Behavioral Decision Making, 16, 3, 215-233 Ben Akiva M. Lerman S. R. (1985) Discrete Choice Analysis: Theory and Application in Travel Demand, MIT Press, Cambridge, Mass. Ben- Akiva, M. and Bolduc, D. (1996) Multinomial probit with a logit kernel and a general parametric specification of the covariance structure. Working Paper. Ben- Akiva, M. and Bierlaire, M. (1999) Discrete choice methods and their applications to short term travel decisions, in: W. Hall (Ed.) Handbook of Transportation Science, pp. 5– 33, Dordrech, Kluwer. Bonsall P., Firmin P, Anderson M., Plamer I., (1997), Validating the results of a route choice simulator, Transportation Research C, 5, 6, 371-387. Bonsall P. (2000), Information systems and other intelligent transport system innovations, in Hensher D. A. & Button K. J. eds., Handbook of Transport Modelling, Pergamon, New York. Busemeyer, J. R., & Townsend, J. T. (1993), Decision field theory: a dynamic- cognitive approach to decision making in an uncertain environment, Psychological Review, 100, 3, 432459. Cascetta, E. and Papola, A. (1998) Implicit availability/ perception logit models for route choice in transportation networks. Paper presented at the 8th World Conference on Transport Research, Antwerp, Belgium. Chu, C. (1989) A paired combinatorial logit model for travel demand analysis, in: Proceedings of the Fifth World Conference on Transportation Research, vol. 4, 295– 309 (Ventura, CA: Western Periodicals Co.). Daganzo, C. F. and Sheffi, Y. (1977) On stochastic models of traffic assignment, Transportation Science, 11, 253– 274. Deakin A. K., (1997), Potential of procedural knowledge to enhance Advanced Traveler Information Systems, Transportation Research Record, 1573, 35-43 Denrell, J. (2006), Learning effects on risk taking, Psychological Review, in press. Denrell J, March J. G. (2001), Adaptation as information restriction: The hot stove effect, Organization Science, 12, 5, 523-538. Erev I., Barron, G. (2005), On adaptation, maximization and reinforcement learning among cognitive strategies, Psychological Review, 112, 4, 912-931. 15 Behavioral insights in route choice models with real-time information Eran Ben-Elia, Yoram Shiftan & Ido Erev Fujii, S., Kitamura, R. (2000), Anticipated travel time, information acquisition and actual experience: Hanshin expressway route closure, Osaka-Sakai, Japan, Transportation Research Record, 1725, 79-85. Horowitz J.L., (1984), The stability of stochastic equilibrium in a two-link transportation network, Transportation Research B, 18, 13-28. Kahneman D, Tversky A (1979), Prospect theory – an analysis of decision under risk, Econometrica, 47, 2, 263-291. Kahneman D, Tversky A (1984), Choices values and frames, American Psychologist, 39, 4, 341-350. Katsikopulos K. V., Duse-Anthony Y., Fisher D. L., Duffy S. A., (2002), Risk attitude reversals in drivers’ route choice when range of travel time information is provided, Human Factors, 44, 3, 466-473. Khattak A. J., Khattak A. J. (1996), Comparative analysis of spatial knowledge and en route diversion behavior in Chicago and San Francisco – Implications for Advanced Traveler Information Systems, Transportation Research Record, 1621, 27-35. Kraan M.,van-der-Zijpp N., Tutert B., Vonk T., van-Megen D. (1999), Evaluating networkwide effects of variable message signs in the Netherlands,Transportation Research Record, 1689, 60-66 Lomax T, Schrank D. (2003), 2002 Urban Mobility Study, Texas Transportation Institute. Lotan T. (1993), Models for route choice behavior in the presence of information using concepts form fuzzy set theory and approximate reasoning, Transportation, 20, 2, 129-155 Mahmassani, H. and Liu, Y. (1998) Dynamics of Commuting Decision Behavior under Advanced Traveler Information Systems, Transportation Research C, 7, 2, 91- 107. McFadden, D., 1978, Modeling the choice of residential location, in: A. Karlqvist, L. Lundquist, F. Snickkars and J. Weibull (Eds) Spatial Interaction Theory and Residential Location, 75– 96 (Amsterdam: North Holland). McFadden, D., K. Train (2000), Mixed MNL models of discrete response, Journal of Applied Econometrics, 15, 5, 447- 470. Myers, J. L., & Sadler, E. (1960), Effects of range of payoffs as a variable in risk taking, Journal of Experimental Psychology, 60, 306– 309. Nakayama S., Kitamura R., Fujii S. (1999), Drivers learning and network behavior: dynamic analysis of the driver-network system as a complex system, Transportation Research Record, 1676, 30-36 Nakayama S., Kitamura R. (2000), Route choice model with inductive learning, Transportation Research Record, 1725, 63-70 Nakayama S., Kitamura R., Fujii S. (2001), Drivers route choice rules and network behavior: do drivers become rational and homogeneous through learning, Transportation Research Record, 1752, 62-68. Peeta S., Ramos J. L., Pasupathy R. (2000), Content of variable message signs and on-line driver behavior, Transportation Research Record, 1725, 102-108. Peeta, S. and Yu, J.W. (2005). A hybrid model for driver route choices incorporating en-route attributes and real-time information effects, Networks and Spatial Economics; 5, 1, 21-40. Prashker J., Bekhor S. (2004), Route choice models used in the stochastic user equilibrium problem: A review, Transport Reviews, 24, 4, 437– 463. Simon H. (1982), Models of Bounded Rationality, MIT Press Cambridge Mass. 16 Behavioral insights in route choice models with real-time information Eran Ben-Elia, Yoram Shiftan & Ido Erev Srinivasan, K. K., Mahmassani H. S.(1999). Role of congestion and information in tripmakers' dynamic decision processes: An experimental investigation, Transportation Research Record, 1676, 43-52. Thorndike, E. L. (1898), Animal intelligence: An experimental study of the associative processes in animals. Psychological Monographs, 2, 4. Tong C. C. (2000), A study of en-route dynamic route choice behavior under the influence of traffic information, PROCEEDINGS OF THE 7TH WORLD CONGRESS ON INTELLIGENT SYSTEMS, HELD TURIN, ITALY, 6-9 NOVEMBER, 2000,. 8p Tversky A., Kahneman D. (1992) Advances in prospect theory – cumulative representation of uncertainty, Journal of Risk and Uncertainty, 5, 297-323. Vovsha, P. (1997) The cross- nested logit model: application to mode choice in the Tel- Aviv Metropolitan Area, Transportation Research Record, 1607, pp. 6– 15. Watling T. R., Van Vuren T. (1993), The modeling of dynamic route guidance systems, Transportation Research C, 1, 2, 159-182. Wardman M., Bonsall P. W, Shires J. D., (1997), Driver response to variable message signs: a stated preference investigation, Transportation Research C.,12, 5 389-405 Wen, C. and Koppelman, F. (2001) The generalized nested logit model, Transportation Research Part B: Methodological, 35, 7, 627– 641. Wong-Wing G. (1999), Driver attitudes towards display formats of real-time traffic information systems, Transportation planning and Technology, 21, 1, 1-19 17 Behavioral insights in route choice models with real-time information Eran Ben-Elia, Yoram Shiftan & Ido Erev Table 1: Three possible travel time scenarios: Scenario Travel Time Ranges (minutes) Fast – 25 min. Slow – 30 min. Safer-Fast 5 15 Risky-Fast 15 5 Low-Risk 5 5 Table 2: Average maxmization rate (full data set) (Average proportion of faster routes’ choices) Scenario Conditions (groups) With information Without information .844 .838 (.165) (.128) .881 .817 (.217) (.128) .966 .880 (.069) (.115) <0.05 - Safer-Fast Risky-Fast Low-Risk Sig. within Sig. between <0.05 Table 3: Average maxmization rate (first 10 trials) (Average proportion of faster routes’ choices) Scenario Safer-Fast Risky-Fast Low-Risk Sig. within Conditions (groups) With information Without information 0.729 .636 (.219) (.173) 0.850 .660 (.228) (.187) .912 .672 (.136) (.196) <0.05 - Sig. between <0.05 <0.05 Table 4: Average maxmization rate (last 50 trials) (Average proportion of faster routes’ choices) Scenario Safer-Fast Risky-Fast Low-Risk Sig. within Conditions (groups) With information Without information 0.873 .914 (.168) (.137) 0.885 .886 (.226) (.154) .986 .954 (.046) (.091) <0.05 - 18 Sig. Between - Behavioral insights in route choice models with real-time information Eran Ben-Elia, Yoram Shiftan & Ido Erev Figure 1: Safer-Fast Avg Proportion Fast Route 1.00 0.95 0.90 0.85 0.80 0.75 0.70 0.65 0.60 with information 0.55 without information 0.50 10 20 30 40 50 60 70 80 90 100 Blocks of 10 trials Figure 2: Risky-Fast Avg Proportion Fast Route 1.00 0.95 0.90 0.85 0.80 0.75 0.70 0.65 0.60 with information 0.55 without information 0.50 10 20 30 40 50 60 Blocks of 10 trials 19 70 80 90 100 Behavioral insights in route choice models with real-time information Eran Ben-Elia, Yoram Shiftan & Ido Erev Figure 3: Low-Risk Avg Proportion Fast Route 1.00 0.95 0.90 0.85 0.80 0.75 0.70 0.65 0.60 with information 0.55 without information 0.50 10 20 30 40 50 60 Blocks of 10 trials 20 70 80 90 100