View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by Periodica Polytechnica (Budapest University of Technology and Economics) Ŕ periodica polytechnica Optimalization of road traffic with the Transportation Engineering applied of reversible direction lanes 38/1 (2010) 3–8 doi: 10.3311/pp.tr.2010-1.01 Zsuzsanna Bede / Géza Szabó / Tamás Péter web: http://www.pp.bme.hu/tr c Periodica Polytechnica 2010 RESEARCH ARTICLE Received 2009-11-03 Abstract 1 Introduction Optimization of traffic on a large public road network is an The heavy increase of the traffic - among many other features undertaking and complex task. Reversible Direction Lane the- - characterizes the developing national economies. At the same ory is an interesting and special method within this subject. This time, often limited resources do not make capacity increase can completely support the fluctuation or alteration in existing of roads possible therefore congestions take shape increasingly congestional direction of traffic dynamics (time of day, seasonal, more frequently because of this. In transport policy, congestion etc.) on existing road surfaces. In such case certain subsys- avoidance receives major importance, and a number of opportu- tems of the main network cease to exist, and subsystems work- nities offer solutions. Here can be enumerated technical devices ing with new connections take their place. This type of routing that form a complicated technical system like on-board, real- therefore changes the system’s structure „in an optimal direc- time, traffic dependent control of vehicles. tion”, but many practical and safety questions arise. A number The principle of most favored innovations is the increased ef- of studies prove that in areas this method is employed, travel fective use of new and existing road networks, homogenization time decreased by 30-40%, waiting time by 40-50%, number of of vehicle traffic, increase in passengers in single vehicles (car- stops by 30-40% compared to previous data. Its benefits were pooling), or the use public transportation. One of the principles also shown in fuel consumption reduced by 15-25%, harmful demanding plain technical backgrounds, which was used since substance emission HC by 15-25%, CO by 3-5%, and NO by 8- the 1920s already in a number of states of The United States 10%. We may not leave the application of this opportunity out of America is the reversible lanes theory [1].We will introduce of consideration in a case when a country’s road infrastructure the historical background of this method in the second chapter. demands considerable developments otherwise. We would like to present the realization of the endeavors being aimed at the avoidance of the congestions in Chapter 2.2. Keywords We will introduce two case studies made in the USA that Reversible lane road traffic traffic control prove the worth of reversible direction lanes in Chapter 2.3. · · Based on the measured values waiting time decreases by half, Acknowledgement in this manner travel time is half as short as well. Besides de- This work is connected to the scientific program of the " De- creasing waiting time the size of traffic has also decreased to its velopment of quality-oriented and harmonized R+D+I strategy half on the road section. It is worth paying attention to not only and functional model at BME" project. This project is supported waiting time, but to the number of stops made. Through this by the New Hungary Development Plan (Project ID: TÁMOP- study it could be determined that continuous traffic flow forms 4.2.1/B-09/1/KMR-2010-0002). since there is a 1/3 decrease in cars forced to make a stop. Based The presented research matter is sponsored by OTKA CNK on these values harmful substance emissions, and fuel consump- 78168 project. tion reaches much more favorable levels. Because of the centralized nature of cities traffic, congestion Zsuzsanna Bede takes shape in the morning towards the center while in the af- Department of Control and Transport Automation, BME, Bertalan L. u. 2., H- ternoon roads leaving out of the city get more congested. In the 1111 Budapest, Hungary afternoon traffic is less busy, and more distributed because of e-mail: [email protected] different sizes of destination areas and different working ours. Géza Szabó Typically with improving lifestyles, people move out of cities to Tamás Péter commute daily from near by towns. This process creates more Department of Control and Transport Automation, BME, Bertalan L. u. 2., H- 1111 Budapest, Hungary commuters so traffic forms throughout larger destinations. Optimalization of road traffic 2010 38 1 3 Taking advantage of the given vehicular traffic size of the di- suited for bridges and within tunnels because at these areas it rections differing in a time moment, it would be beneficial to is desirable to maintain adequate capacity within the restricted create interchangeable direction lanes that would take into con- right-of-ways of work zones. sideration current traffic flow, and provide optimum room for In Illinois, a 6,000 ft movable concrete barrier was used dur- both directions. Reversible lanes must be designed based on en- ing the rehabilitation of the McClugage Bridge. The barrier vironmental and social demands of a location. We present some which could be realigned in about 25 min with only minor dis- procedures taking these claims into consideration, emphasizing ruptions to traffic was used to serve directionally unbalanced the Hungarian conditions in the third Chapter. volumes during the morning and afternoon peak periods [4]. The second most recent usage of RLS has been the purpose 2 Development and application of reversible lane sys- of emergency traffic management. Largely the result of the traf- tem fic jams was associated with natural disasters as hurricanes (15 2.1 Historical overview states have developed plans for the use of contraflow for hurri- The spread of vehicles conducived to formation of larger ve- cane evacuation) and manmade hazards, including various nu- hicular traffic size which caused congestions [3]. The use of clear, biological, chemical, and terrorist threats. reversible lanes was one of the primary methods of the last cen- One of the advantages to reversing flow on a freeway is the tury used to handle peak period traffic flows. restricted access into the travel lanes. Freeway operating speeds It was first tested by Ralph T. Dorsey in Downtown Los An- are typically much higher than arterial roadways, which lim- geles in 1928. When the traffic was bad at the morning in one of its the required manpower and quantity of control elements re- the directions an extra lane was provided which was used dur- quired for the reversal, however that is the major drawback. As a ing the afternoon by the opposite traffic. Metal-based stanchions result, transition period and points become more critical element were initially used to delineate the temporary division between of the design and management plan. opposing traffic flows during the early period, and after 1950 the The frequency of the largest cultural or sport events, that oc- new traffic cones were deployed. The Reversible Lane System cur annually or seasonally, typically does not warrant the con- (RLS) has been used all over the word which specific liens in struction of additional lanes or complex control systems (Fig. 2). that it can increase the capacity of roads [4]. The RLS can be There are some exceptions to this rule, particularly for arenas in used (see Fig. 1): urban areas. The scheduling of more frequent events justified the added expense of a permanent system in these instances. – against congestions (which are established in peak hours, dur- Unlike in Event Traffic Management (where events occur an- ing monumental events) nually or seasonally), at Peak Period Management these events – temporary divert of traffic (respectively for evacuate of disas- are ordinary. ter area). The management of peak hour traffic are particularly effec- tive and most commonly used on arterial roadways and free- ways (like in Washington, DC where reversible lanes have been Construction Zone Traffic Management Emergency Traffic Ma na gement both popular and successful), rather than local traffic. Typical for Peak Period Management that the direction of traffic in lanes TEMPORARY is routinely converted during the morning and evening commute Diverted Traffic periods. Controlled Traffic On this freeway, two lanes between the directional lanes are dedicated for inbound transit in the morning, then outbound in the afternoon. At the reversible lanes traffic can enter and depart PERMANENT at several points. Between the reversible and directional freeway Peak‐Period Traffic Management Event Zone Traffic Management lanes the access is controlled by gated ramp crossovers and by Fig. 1. Characteristics of applications of Reversible Lanes signal controlled reversible ramps between the reversible free- way lanes and grade separated arterial roadways (see Fig. 3). During the use of RLS the basic principle is simple; neverthe- These segments are relatively short (about two to three miles less it requires clear planning and operation. The traffic signals in length) and operate on a one-way in basis from 7:00 to 9:00 and marks have to give appropriate information to driver about a.m. and a one-way out basis from 4:00 to 6:00 a.m. actual conditions and must not allow going in the face of direc- With assistance from DC Park Police the movements into and tion of the traffic under any circumstances. out of the segments are controlled at signalized intersections [4]. An other unique example of RLS used on a roadway that is 2.2 Use of Reversible Direction Lanes operated as a balanced four-lane corridor that works out a smart One of the most current ways around the world of the usage idea that allows residents to on-street parking during non-peak of RLS is the construction work zone.