Economic resilience to transportation failure: a computable general equilibrium analysis

This study develops and applies a multimodal computable general equilibrium (CGE) framework to investigate the role of resilience in the economic consequences of transportation system failures. Vulnerability and economic resilience of different modes of transportation infrastructure, including air, road, rail, water and local transit, are assessed using a CGE model that incorporates various resilience tactics including modal substitution, trip conservation, excess capacity, relocation/rerouting, and service recapture. The linkages between accessibility, vulnerability, and resilience are analyzed. The model is applied to the transportation system failures in the aftermath of Hurricane Katrina to illustrate its capabilities. The analytical framework, however, has broader applications and can provide insights for resource allocations to enhance emergent responses to unexpected events and to improve resilient design of transportation infrastructure systems.     

Bayesian imputation of non‐chosen attribute values in revealed preference surveys

Obtaining attribute values of non‐chosen alternatives in a revealed preference context is challenging because non‐chosen alternative attributes are unobserved by choosers, chooser perceptions of attribute values may not reflect reality, existing methods for imputing these values suffer from shortcomings, and obtaining non‐chosen attribute values is resource intensive. This paper presents a unique Bayesian (multiple) Imputation Multinomial Logit model that imputes unobserved travel times and distances of non‐chosen travel modes based on random draws from the conditional posterior distribution of missing values. The calibrated Bayesian (multiple) Imputation Multinomial Logit model imputes non‐chosen time and distance values that convincingly replicate observed choice behavior. Although network skims were used for calibration, more realistic data such as supplemental geographically referenced surveys or stated preference data may be preferred. The model is ideally suited for imputing variation in intrazonal non‐chosen mode attributes and for assessing the marginal impacts of travel policies, programs, or prices within traffic analysis zones. Copyright © 2012 John Wiley & Sons, Ltd.     

法拉利生病记

我有些朋友在香港买很贵的车，但到了内地却选择相对很便宜的车。有时候我不太能理解他们，为什么买得起千万的豪华跑车。到了内地却开辆中产阶级的车，这次总算知道了一个重要原因。     

反对的权利

赛车这个行业，跟世界上所有的行业一样，也有歧视和不平等。特别是对于人行不久而又没有强大幕后支持的人来说，你有时会觉得：为什么他们可以那样做而不允许我那样做？为什么有些人做得不好反而被赞扬而自己成绩这么好却会被贬低？世界就是不公平的。在你非常有理的时候，你有权利反对。反对之后也许短期是个对你有利的结果，但你要为此承担长期的后果。     

A recursive, cell processing model for predicting freeway travel times

Travel time information influences driver behaviour and can contribute to reducing congestion and improving network efficiency. Consequently many road authorities disseminate travel time information on road side signs, web sites and radio traffic broadcasts. Operational systems commonly rely on speed data obtained from inductive loop detectors and estimate travel times using simple algorithms that are known to provide poor predictions particularly on either side of the peak period. This paper presents a new macroscopic model for predicting freeway travel times which overcomes the limitations of operational ‘instantaneous’ speed models by drawing on queuing theory to model the processing of vehicles in sections or cells of the freeway. The model draws on real-time speed, flow and occupancy data and is formulated to accommodate varying geometric conditions, the relative distribution of vehicles along the freeway, variations in speed limits, the impact of ramp flows and fixed or transient bottlenecks. Field validation of the new algorithm was undertaken using data from two operational freeways in Melbourne, Australia. Consistent with the results of simulation testing, the validation confirmed that the recursive model provided a substantial improvement in travel time predictions when compared to the model currently used to provide real-time travel time information to motorists in Melbourne.     

Design charts for estimating transportation planning statistics from area population

Utilizing data collected for urban transportation studies in Ontario, regression analysis has been used to establish relationships between the daily number of person trips in an urban area and the area population. In particular the number of trips by auto drivers, auto passengers and mass transit riders have been investigated. Further, auto driver trips have been stratified into the following destination trip purposes: return home, work and related business, shopping, social-recreational and miscellaneous. The results of this analysis have been used to prepare a set of design charts. These charts are presented graphically and in the form of a nomogram. The accuracy of these charts has been investigated and found satisfactory for most planning purposes.     

乱战——Confusing Race

今年亚洲超级跑车挑战赛的开幕战在4月,也是我参赛有史以来第一次,比赛就在眼前,而很多车手还用疑惑的腔调互相打听：我们的比赛是否能如期进行？     

怎样看出赛车天分

时常会听到赛车圈里的前辈老师或者有经验的赛车手提到某个年轻的新生车手是否有赛车天分。中国的赛车历史很短,深谙赛车之道的人也不多,怎么能判断一个刚成年或者未成年的孩子是否有赛车天分呢？     

三驾马车——Three Different Ferrari Scuderias

去年到今年,最热门的超级跑车就是法拉利430的Scuderia了。去年夏天,Scuderia刚进中国,我在上海郊外道路上开过一辆蓝色的Scuderia;去年11月,在上海F1赛车场试驾了一辆红色的Scuderia;这次,我在香港街道上开了一辆黑色的Scuderia。     

测试锐迪可——Test Drive a Radical Racing Car

2009年,从赛车的繁华表象上根本看不到金融危机：我忍痛割舍的超级跑车挑战赛今年变成了亚洲GT3,很多车手更换了新赛车,不管是300万元还是400万元的新赛车,照样在比赛中撞得一塌糊涂,因为名次比损伤更重要。今年还新增了4、5项新赛事,项项都是收钱的赛事,我被邀请试车的锐迪可就是其中之一。