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EFFECT OF DARKNESS ON THE SPEED-FLOW RELATIONSHIP FOR A TWO-LANE, TWO-WAY INTERURBAN ROAD

Penulis : DAS'AT WIDODO
Kontributor / Dosen Pembimbing :
  • Supervisor: Trisno Soegondo
  • Supervisor: Karl - Lennart Bang
Jenis Koleksi : Tesis
Penerbit : Sistem dan Teknik Jalan Raya
Fakultas : Fakultas Teknik Sipil dan Lingkungan
Subjek :
Kata Kunci : Free flow speed, bunching characteristic, overtaking maneuver.
Sumber :
Staf Input/Edit :   Irwan Sofiyan
File : 1 file
Tanggal Input : 12 Feb 2005

1995_TS_PP_WIDODO_1.pdf
PUBLIC Irwan Sofiyan

Darkness may affect the capacity, free flow speed, bunching characteristic, overtaking maneuver etc. This thesis tries to study the effect of darkness. The main objectives of the thesis are; to compare free flow speed, speed flow relationship and capacity in daylight and in darkness, also to study how vehicle bunching characteristic are affected by darkness. Data was collected from road segment which had condition as below : - Two-lane, two-way undivided interurban road. - Flat terrain and straight. - Side friction was low. - Road width was approx. 7 meter with unpaved shoulder width 2-3 m. The site survey was chosen in link between Cikampek and Purwakarta at km 8 400 near Cikampek. Data were obtained in two condition; in daylight and in darkness. Data in the same site ( in daylight condition ) were also obtained from Indonesia Highway Capacity Manual Project data bank. The result of this study shows that differences of capacity, free flow speed, speed flow relationship, overtaking maneuver etc, between darkness and daylight are significant. Speed for light vehicle was used as dependent variable in the analysis. Speed flow relationship in daylight is flatter with slope -0.01261 than in darkness with slope -0.01382 ( linear regression ) in the flow range between 950-1200 pcu/h. Base free flow speed of LV in darkness ( 60.1 km/h ) is lower than in daylight ( 71.7 km/h ). Capacity in darkness may be 13 % lower than in daylight, it can be seen from average time headway in platooning condition. In darkness, average time headway is 2.1 seconds and in daylight 1.83 seconds. At the same speed level, the distance headway in daylight is 13 % lower than in darkness. It indicates that in daylight driver is braver than in darkness. At flow range between 800 - 1200 veh/h, overtaking maneuver in darkness is more difficult than in daylight, which can be seen from degree of bunching-flow relationship. At the same flow (for instant 800 veh/h), the degree of bunching in darkness ( 0.58 ) is higher than in daylight ( 0.54 ).

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