Does travel closer to TOD have lower CO2 emissions? Evidence from ride-hailing in Chengdu, China.

Despite contributions to reducing private car dependency and carbon emissions, impacts of transit-oriented development (TOD) on ride-hailing usage are largely overlooked in existing studies. Using massive ride-hailing trips data in Chengdu, the influence of subway proximity on vehicle kilometers traveled (VKT) and corresponding CO2 emissions of ride-hailing is examined at the disaggregated level. Similarly, moderated multiple regression is adopted to investigate the interaction effects of subway proximity at pick-up and drop-off on VKT of ride-hailing. Results suggest that for each additional kilometer in subway proximity at pick-up/drop-off position, the VKT of ride-hailing trips is reduced by 0.315 km/0.273 km, resulting in the CO2 emission reduction of 0.063 kg/0.055 kg. Moreover, the influence of pick-up proximity on VKT change is negatively moderated by drop-off proximity and vice versa. Our results suggest that the carbon emission reduction can benefit from "T (Transit)" however the problem of regional imbalances in "D (Development)" needs to be addressed.

Experiments on individual strategy updating in iterated snowdrift game under random rematching.

How do people actually play the iterated snowdrift games, particularly under random rematching protocol is far from well explored. Two sets of laboratory experiments on snowdrift game were conducted to investigate human strategy updating rules. Four groups of subjects were modeled by experience-weighted attraction learning theory at individual-level. Three out of the four groups (75%) passed model validation. Substantial heterogeneity is observed among the players who update their strategies in four typical types, whereas rare people behave like belief-based learners even under fixed pairing. Most subjects (63.9%) adopt the reinforcement learning (or alike) rules; but, interestingly, the performance of averaged reinforcement learners suffered. It is observed that two factors seem to benefit players in competition, i.e., the sensitivity to their recent experiences and the overall consideration of forgone payoffs. Moreover, subjects with changing opponents tend to learn faster based on their own recent experience, and display more diverse strategy updating rules than they do with fixed opponent. These findings suggest that most of subjects do apply reinforcement learning alike updating rules even under random rematching, although these rules may not improve their performance. The findings help evolutionary biology researchers to understand sophisticated human behavioral strategies in social dilemmas.

A system dynamics approach to scenario analysis for urban passenger transport energy consumption and CO2 emissions: A case study of Beijing.

With the accelerating process of urbanization, developing countries are facing growing pressure to pursue energy savings and emission reductions, especially in urban passenger transport. In this paper, we built a Beijing urban passenger transport carbon model, including an economy subsystem, population subsystem, transport subsystem, and energy consumption and CO2 emissions subsystem using System Dynamics. Furthermore, we constructed a variety of policy scenarios based on management experience in Beijing. The analysis showed that priority to the development of public transport (PDPT) could significantly increase the proportion of public transport locally and would be helpful in pursuing energy savings and emission reductions as well. Travel demand management (TDM) had a distinctive effect on energy savings and emission reductions in the short term, while technical progress (TP) was more conducive to realizing emission reduction targets. Administrative rules and regulations management (ARM) had the best overall effect of the individual policies on both energy savings and emission reductions. However, the effect of comprehensive policy (CP) was better than any of the individual policies pursued separately. Furthermore, the optimal implementation sequence of each individual policy in CP was TP→PDPT→TDM→ARM.

Analytical investigation of the open boundary conditions in the Nagel-Schreckenberg model.

We theoretically investigate the mechanism of the open boundary conditions in the deterministic Nagel-Schreckenberg model, which was studied mainly by numerical simulations before. Our studies concentrate on the open boundaries and have found an effective approach for deducing the analytical expression of inflow. We also raise a removal rule which is analyzable. These findings provide a theoretical explanation of the behaviors of the open boundaries and allow the exact prediction of the traffic state by using the injection rate and the removal rate.

The effectiveness and influencing factors of a penalty point system in China from the perspective of risky driving behaviors.

Many countries have adopted penalty point systems (PPS) to deter drivers from breaking traffic laws. To investigate the effectiveness of PPS on reducing illegal driving behavior, this study analyzed traffic violation data of a Chinese city in 2017. This analysis revealed that 1) risky driving behaviors (RDBs) are among the main causes of traffic violations and 2) almost half of the offenders with multiple violations committed the same traffic rule violations more than once. To further explain these phenomena, a survey in another Chinese city-Tianjin-was conducted. Considering the fact that most types of RDBs will, if detected by the authorities, result in traffic violations, the present study investigated the influence of a PPS, represented by penalty experience (PE), on traffic violation behaviors from the perspective of RDBs. Moreover, the impact of cognitive processes on driving behaviors via self-efficacy was considered. We found that drivers' PE is positively associated with their RDBs and that offenders with more PE are more inclined to commit RDBs; we further observed that self-efficacy partially mediates the relationship between PE and RDBs. However, no gender difference in the effect of PE on RDBs was discovered, thus indicating that PE has the same effect on male and female drivers. Based on these findings, some strategies are suggested (such as the Increasing Block Penalty Points Policy) to improve the effectiveness of the PPS.

Prospect theory based estimation of drivers' risk attitudes in route choice behaviors.

This paper applied prospect theory (PT) to describe drivers' route choice behavior under Variable Message Sign (VMS), which presented visual traffic information to assist them to make route choice decisions. A quite rich empirical data from questionnaire and field spot was used to estimate parameters of PT. In order to make the parameters more realistic with drivers' attitudes, they were classified into different types by significant factors influencing their behaviors. Based on the travel time distribution of alternative routes and route choice results from questionnaire, the parameterized value function of each category was figured out, which represented drivers' risk attitudes and choice characteristics. The empirical verification showed that the estimates were acceptable and effective. The result showed drivers' risk attitudes and route choice characteristics could be captured by PT under real-time information shown on VMS. For practical application, once drivers' route choice characteristics and parameters were identified, their route choice behavior under different road conditions could be predicted accurately, which was the basis of traffic guidance measures formulation and implementation for targeted traffic management. Moreover, the heterogeneous risk attitudes among drivers should be considered when releasing traffic information and regulating traffic flow.

Reply to "Comment on 'Analytical investigation of the open boundary conditions in the Nagel-Schreckenberg model' ".

Recent reports [N. Jia and S. Ma, Phys. Rev. E 79, 031115 (2009); T. Neumann and P. Wagner, Phys. Rev. E 80, 013101 (2009)] have different opinions on the exact analytical solution of the inflow in the Nagel-Schreckenberg model with expanded left boundary condition. In the current study, the different implementations of the "expanded left boundary" are proven to cause the confliction. Detailed analyses show that both reports are reasonable, depending on whether the rule "clear the minisystem first" is applied.

Traffic-light boundary in the deterministic Nagel-Schreckenberg model.

The characteristics of the deterministic Nagel-Schreckenberg model with traffic-light boundary conditions are investigated and elucidated in a mostly theoretically way. First, precise analytical results of the outflow are obtained for cases in which the duration of the red phase is longer than one step. Then, some results are found and studied for cases in which the red phase equals one step. The main findings include the following. The maximum outflow is "road-length related" if the inflow is saturated; otherwise, if the inbound cars are generated stochastically, multiple theoretical outflow volumes may exist. The findings indicate that although the traffic-light boundary can be implemented in a simple and deterministic manner, the deterministic Nagel-Schreckenberg model with such a boundary has some unique and interesting behaviors.

Analytical results of the Nagel-Schreckenberg model with stochastic open boundary conditions.

The deterministic Nagel-Schreckenberg model with stochastic open boundary conditions is investigated in a mostly analytical way. By means of the Markov Chain, we model the working process of the stochastic open boundaries. First, the analytical expression of the free-flow density profiles is derived. Then, we discuss theoretically how the right boundary determines the traffic capacity, global density, and density profiles. For these features, the analytical and numerical results agree well. This paper implies that the deterministic Nagel-Schreckenberg model with stochastic open boundaries is almost totally analyzable.