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91.
A driver is one of the main components in a transportation system that influences the effectiveness of any active demand management (ADM) strategies. As such, the understanding on driver behavior and their travel choice is crucial to ensure the successful implementation of ADM strategies in alleviating traffic congestion, especially in city centres. This study aims to investigate the impact of traffic information dissemination via traffic images on driver travel choice and decision. A relationship of driver travel choice with respect to their perceived congestion level is developed by an integrated framework of genetic algorithm–fuzzy logic, being a new attempt in driver behavior modeling. Results show that drivers consider changing their travel choice when the perceived congestion level is medium, in which changing departure time and diverting to alternative roads are two popular choices. If traffic congestion escalates further, drivers are likely to cancel their trip. Shifting to public transport system is the least likely choice for drivers in an auto-dependent city. These findings are important and useful to engineers as they are required to fully understand driver (user) sensitivity to traffic conditions so that relevant active travel demand management strategies could be implemented successfully. In addition, engineers could use the relationships established in this study to predict drivers’ response under various traffic conditions when carrying out modeling and impact studies. 相似文献
92.
Coastal erosion threatens many sandy beaches and the ecological, economic, social and cultural amenities they provide. The problem is especially chronic in South Florida. A frequent solution for beach restoration involves sand replacement, or nourishment, but is temporary, expensive, and has usually been funded by governmental sources. However, as such agencies reduce their share and require more local funding, beach nourishment must rely on other funding sources, including beach recreationists. Our study characterized three South Florida beaches and probed visitor willingness-to-pay for beach nourishment. We found that even beaches within close proximity attract different user types. Users are amenable to higher fees if they lead to greater resource protection. 相似文献
93.
To accurately estimate real-world vehicle emission at 1 Hz the road grade for each second of data must be quantified. Failure to incorporate road grade can result in over or underestimation of a vehicle’s power output and hence cause inaccuracy in the instantaneous emission estimate. This study proposes a simple LiDAR (Light Detection And Ranging) – GIS (Geographic Information System) road grade estimation methodology, using GIS software to interpolate the elevation for each second of data from a Digital Terrain Map (DTM). On-road carbon dioxide (CO2) emissions from a passenger car were recorded by Portable Emission Measurement System (PEMS) over 48 test laps through an urban-traffic network. The test lap was divided into 8 sections for micro-scale analysis. The PHEM instantaneous emission model (Hausberger, 2003) was employed to estimate the total CO2 emission through each lap and section. The addition of the LiDAR-GIS road grade to the PHEM modelling improved the accuracy of the CO2 emission predictions. The average PHEM estimate (with road grade) of the PEMS measured section total CO2 emission (n = 288) was 93%, with 90% of the PHEM estimates between 80% and 110% of the PEMS recorded value. The research suggests that instantaneous emission modelling with LiDAR-GIS calculated road grade is a viable method for generating accurate real-world micro-scale CO2 emission estimates. The sensitivity of the CO2 emission predictions to road grade was also tested by lessening and exaggerating the gradient profiles, and demonstrates that assuming a flat profile could cause considerable error in real-world CO2 emission estimation. 相似文献
94.
介绍涵盖船舶/海工建造、运行及拆解全寿命周期3D测试技术。阐述基于3D激光扫描非接触式实船3D船形测试,以及基于水声学技术的水下3D测试技术研究进展。 相似文献
95.
铁路货运服务质量关系到铁路企业形象和效益。采取定性和定量相结合的研究方法,建立功能质量测评体系,根据货运部门自身的特点建立相应的技术质量量化测评体系,最终将指标数量值转化成评定的等级。并通过实例验证了该评价方法的现实性和可操作性。 相似文献
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97.
认为:随着电子技术和传感技术的进步,汽车诊断技术及设备发展非常迅速,在实行技术状况临测、不解体诊断、视情维修、强化管理等方面起着重要作用。重点介绍了功率平衡、点火系统、气缸、燃油供给系及起动系的检测诊断的方法、项目和设备。 相似文献
98.
99.
数字摄影测量在交通事故现场勘查中的应用 总被引:5,自引:0,他引:5
对于交通事故现场的处理,目前主要使用拉皮尺、目击调查以及使用影像记录等简单的勘查手段,这对需要快速记录现场情况,然后迅速疏通交通,并在事后进行事故分析和责任认定等造成一定的困难。文章将数字摄影测量中的双像立体和单像纠正技术引入现场勘查,通过事后恢复有用的几何信息以及绘制符号化事故现场图,实现事故现场的可视化重现,为事故分析、责任认定和案例存档等提供了有效途径。为说明该方法的可行性和有效性,文中介绍了相关软件,并通过实验证明该技术具备精度高。自动化程度高以及使用简单等特点。 相似文献
100.
SHRP沥青性能分级量度的探讨 总被引:4,自引:1,他引:4
利用SHRP胶结料试验仪器,基于表征沥青路用性能的流变力学指标,测试了不同标号、不同老化程度的道路沥青在一定适用温度范围内的性能特征.分析结果表明,胶结料高温指标车辙因子G*/sinδ对于不同标号沥青的响应程度较低温指标劲度模量S明显偏大.也即,6℃量度的SHRP温度分级在反应不同沥青使用高温与使用低温性状的差异时并不协调.进一步分析得出,与目前针入度级方法比较,在评定试验沥青低温性能的量度方面,SHRP方法的温度分级量度偏大. 相似文献