«چند‌سياستي» رويكردي نوين در مديريت تقاضاي حمل‌ونقل شهري

MULTI-INSTRUMENTALITY, A NEW APPROACH IN TRANSPORTATION DEMAND MANAGEMENT

به‌منظور بهبود شرايط ترافيكي شهرها، اخيراً رويكرد نوين‌ِ چند‌سياستيِ مديريت تقاضاي حمل‌ونقل به‌عنوان جايگزين رويكرد تك‌سياستي مطرح شده است. در اين مطالعه طراحي روش اجرا و شناساييِ ميزان اثرات چند‌سياستي مديريتي هم‌زمان در مديريت تقاضاي حمل‌ونقل شهري بررسي شده است. در اين راستا علاوه بر اثرات اصلي سياست‌ها، آثار تركيبي سياست‌ها نيز در طرح آزمايشي مطالعه مورد توجه قرار گرفته و پنج سياست مديريتي حمل‌و‌نقل شامل: سياست‌هاي كاهش زمان سفر سيستم‌هاي همگاني، بهبود دسترسي به سيستم‌هاي همگاني، قيمت‌گذاري سوخت، قيمت‌گذاري پاركينگ، و اخذ وروديه به مركز شهر در سفرهاي كاري به مركز شهر تهران بررسي شده است. با گردآوري رجحان‌هاي بيان‌شده 366 نفر استفاده‌كننده از سواري شخصي، مدل انتخاب وسيله‌ي مسافران در قالب يك مدل لوجيت چندگانه تهيه شد و نمودارهايي براي نشان‌دادن كاربرد مدل براي سياست‌گذاري ارايه ‌شده است.

Congestion, when driving a car, is a common problem for megalopolis citizens because it imposes environmental and social costs, such as air and noise pollution, depletion of energy, road casualties and daily delays. Because of limitations on expanding transportation networks, over the past several decades, policymakers and transportation planners around the world have attempted to reduce congestion by proposing transportation demand management (TDM) policies. Today, the integration of TDM policies as a realistic and effective approach is a challengeable issue in urban policy studies. In fact, interaction between policies that are not addressed broadly in an integration context plays a main role in the outcome of TDM policy packages. On the other hand, different individual aims in daily trips, city development, variation of land use, and different levels of decision making in transportation, often leads to implementation of more than one TDM policy at a time. This study examines the role of TDM policy packages on commuter mode choice in the city of Tehran. The analysis is based on the results of a stated preference survey developed by efficient designers, as a specialized design type of experimental approach, which allows assessing all two-way interactions of policies, as well as their main effects. Five policies consist of increasing parking cost, increasing fuel cost, cordon pricing, transit time reduction and transit access improvement are assessed when considering six modes of transport to the work place. A multinomial logit model was developed for 366 commuters who regularly go to their workplace in the centre of the city. In addition to a number of commuting and contextual variables, the model shows that the policiesʹ main effect and their interactions are significant in mode choice, and are effective. The results show that for car users who faced TDM policies, all five studied TDM policies were factors in the mode choice process. The model shows that in considering car usage, push policies play a main role, and pull policies do not. Results of the model also show that to implement a single policy, cordon pricing is the most effective in decreasing car usage. The marginal values of policies are also presented, and three graphs are provided to show the results of the implementation of the model.