) كل المركب تمر في ربع س ع PHF (minimum) = 0.25 ( V = V 15

Transcription

1 High way and Transportation II (Lab.) LCIV 4034 Lecture 1 The course will contain the following: 1- Project: Geometric design of highway. 2- Laboratory experiments. 3- Discussion. (If required). م ال ر ب ن التصم ال ندس اإلنش ئ ل طر التصم ال ندس : ه التصم الذ ت بتحد د عدد عرض مس ر الطر كذل تصم م طع الطر األف الرأس العرض. التصم اإلنش ئ : ه التصم الذ ت بتحد د طب الرصف المن سب ل طر سم ك كل طب رصف بم تن س مع حج المر ر ع الرص خ اص م دة الرصف. Introduction: Definitions: Speed: Rate of motion(mph, km/hr). There are three types of speed: ) سرع لحظ ) - Spot speed. It is the instantaneous speed of a vehicle at a specific location. - Running speed. The average speed maintained over a given route while the vehicle is in motion. - Average Journey Speed. Distance traveled divided by the total time taken to complete the distance. Volume, Flow: The total number of vehicles that pass over a given point of high way during specific time interval. Rate of flow: the equivalent hourly rate at which vehicles pass over a given point of highway during a given time period less than 1hour, usually 15min Peak hour factor (PHF): the ratio of total hourly volume to the maximum 15-minute rate of flow within the hour. Peak hour factor (PHF) 4 V 15 volume during peak hour (peak rate of flow within peak hour) ) كل المركب تمر في ربع س ع PHF (minimum) = 0.25 ( V = V 15 PHF (maximum) = 1 ( V=4V 15 ب لتس ي األرب ع ع ي م زع المركب ) Steady flow

2 Example: Time volume Rate of flow 6:00-6: =1500 6:15-6: :30-6: :45-7: V=1557 PHF Density, concentration: (K,D): the number of vehicles occupying a given length of highway at a given عدد الس را الم ج دة ف ط ل مع ن من الش رع ف لحظ مع ن instant. (Veh/km) Level of Service: LOS is a qualitative measure that describes operational conditions within a traffic stream and their perception by drivers or / and passengers. Level of service has six levels, the first one is A, and the worst one in F. ADT (average daily traffic): the average of 24hour counts collected over a number of days greater.(مجم ع السي را خالل عدة أي أقل من سن / عدد هذه األي than 1day and less than 1-year ( AADT (average annual daily traffic): the average of 24-hour counts collected over a year. It is used to: 1- Study The accidents and obstacles. 2- Design and evaluation of highway. 3- Study the benefits that may come from the road.

3 Number of lanes calculation ع حس ع ت ج ت ي ا ي ع ي ا ا ك :ع (veh/hr) PHV ا ك ع ع عي ا س ا يج فع س ا سي ا ك س. PHV after n years=phv current n = number of years required. (after 20 years for example). g = traffic growth rate (given in the problem). PHF = peak hour factor N = number of lanes in the heaviest direction For example, if the street is 6-lane highway, N = 3 (3 in each direction), and if the street is 4-lane highway, N = 2 (2 in each direction) and so on. fp = drivers population factor (usually taken 1). fhv = heavy vehicle adjustment factor and it is calculated as follows: ا ع س ج ا ؤك passenger cars only قي حس ق ح ا ثقي صا كا ا ت في ي في ا ط يق ا تي ا ا احج اخ ت ت ف ع ا passenger cars passenger cars ا ى أ اع ا ثقي ا ك تح ي ا ع ا يست ت ي ت تقسي ا ك ا ثقي ا ى قس ي : 1. Trucks (heavy vehicles) and Busses, and denoted by T 2. Recreational Vehicles, and denoted by R. So, PT= percent of trucks(heavy vehicles)and busses (given in the problem) PR = percent of recreational vehicles (given in the problem)

4 أحي ق ت س ع ا ت في ف حيث أ ك ا ع ي ع ثقي ص في ا سأ. ج اال ت يج ت ي passenger cars ي ا ت قي عا ET= passenger cars equivalent for trucks (heavy vehicles)and busses. ER= passenger cars equivalent for recreational vehicles. The values of ET and ER can be determined from the following table: ( type of terrain ) األ ط يع ع ع ى أس سي تعت ا قي أ الحظ Example : Multilane highway has a traffic volume of 2800 veh/hr (in the peak direction) in The annual growth rate of traffic volume is 4% and design period = 10 years. Given the following information: Level terrain, 10 percent trucks PHF = 0.95 Measured FFS = 70 km/hr How many lanes should be added in order to reach level of service C? PHV after n years = PHV current PHV after 10 years=2800 = veh/hr

5 PT= 10%=0.1, PR= 0%=(not given) To find ET and ER, we want to know the type of terrain. The terrain is level (as given) ET= 1.5 and ER=1.2 (from table). The required is to reach LOS C, when PHV = 4145 veh /hr At LOS (at FFS = 70) the value of Vp is 1080 (as shown in figure below) =