【正文】 7 50m ? V/C ratio (負荷度） defined as the ratio of current volume or projected demand to the capacity ? Free flow speed (自由流速度） defined as an average speed measured when flow is less than 1000 vehicles per hour per lane ? Maximum service flow rate (最大服務流率） defined as the capacity for the given level of service from A to E ? Ideal conditions (理想條件） width of lane, lateral clearance (側向凈空） , number of lanes, percent of heavy vehicles, median type(中間分隔帶） , frequency of interchange (立交間距 ) or access points (出入口數(shù)量） ? Service flow rate (服務流率） and service volume (服務流量） i i H V pS F M S F N f f? ? ? ?iiS V S F P H F??? Two types of analysis 1. Operational analysis: 2. Design analysis: pH V pVvP H F N f f? ? ? ?i H V pDDHVNP H F M S F f f? ? ? ?? Adjustment factor for heavy vehicles ? Adjustment factor for driver’s population refers to those unfamiliar driver (nonlocal) )1()1(11??????? RRTTHV EPEPfpf? Steps for operational analysis step one determine FFS step two determine demand flow rate step three – find level of service LDNLCLW ffffBFFSFFS ?????AMLCLW ffffBF FSFF S ?????? Steps for design analysis step one determine FFS step two determine MSF step three – find number of lanes N Capacity amp。 Level of Service at merge, diverge and weave area ? Merging (合流） occurs when two separate traffic streams join to form a single stream ? Diverging （分流） occurs when one traffic stream separates to form two separate traffic streams ? Weaving （交織） occurs where a merge area is closely followed by a diverge area Merge Inf l uence A r ea VR VF V1, 2 VFO VR 1, 2=VR+V12 VR 1500 ft . VF V1, 2 VFO 1500 ft . L (2500 ft .) C row n l i ne F i gur e R am p w eave f or T ype A Weaving section (交織區(qū)） ? Definition merge area is closely followed by diverge area (L2500 ft.) ? Configuration 3 types and 7 forms ? Steps in weaving analysis 1. Convert volumes to flow rates using 2. Assume operation is unconstrained and calculate speeds of weaving and nonweaving using dcbi LNvVRaW)()1( ??WFFSSi ????11015PHVii ffP H FVv??? 3. Calculate weighted average speed using 4. Calculate density using 5. Determine capacity of weaving section using wwnwnwwnwSvSvvvS???SNvD ?P H Fffcc pHVbh ????Merge amp。 diverge ? Definition for the socalled “isolated” merge or diverge area ? Two rightmost lanes are the focus ? Steps of analysis 1. Calculate demand flow rate for lanes 1 and 2 using FMF PVV ??2,1FDRFR PVVVV ???? )(2,1 2. Capacity check by paring demand flow rates with critical capacity values given in Table 3. Calculate density and determine level of service using 4. Determine expected speed using equations in Table and Table 1 , 25. 47 5 0. 00 73 4 0. 00 78 0. 00 62 7R R aD V V L? ? ? ? ? ?1 , 52 08 6 09RdD V L? ? ?Chapter 7. Traffic control devices ? Definition and categories ? MUTCD ? Traffic markings ? Traffic signs ? Traffic signals ? Traffic control devices defined as the media (媒介） by which traffic engineers municate with road users functioned as the conveyor （傳遞者） of traffic law and regulations ? Three categories traffic markings (交通標線） traffic signs (交通標志） traffic signals (交通信號） MUTCD ? Manual on Uniform Traffic Control Devices ? Developed over 80 years ? Uniformity ? Warranty Markings ? Longitudinal markings (縱向標線） ? Transverse markings (橫向標線） ? Object markers and delineators （物標和反光燈） Reverse lane （潮汐車道） Traffic signs ? Regulatory signs （法令標志） ? Warning signs （警告標志） ? Guide signs （指路標志） Traffic signals ? Traffic control signals ? Pedestrian signals ? Signal at freeway entrance ? Signal for draw bridges (開啟橋 ) ? Laneuse control signal (車道燈 ) ? Flashing beacon (閃耀燈 ) Chapter 8. Intersection design ? Introduction of intersection control ? Basic principles of intersection signalization ? Fundamentals of signal timing and design ? Demo of puter software Introduction to intersection control ? Basic rule of road （基本通行規(guī)則） 1. Driver on the left yield on the right 2. Through traffic has rightofway over turning movements 3. Sight distance should be met. (sight triangle 視距三角形 ) )()(22GFSStSddan dd fiiBA ?????? STOP and YIELD signs 1. Twoway STOP sign (TWSC 二路停車 ) 2. YIELD sign 3. Multiway STOP sign （多路停車） 4. Capacity of TWSC a. Priority of movements for TWSC b. Conflicting volume （沖突流量） c. Critical gap and followup time （臨界可接受間隙與隨車時距） d. Potential capacity （可能通行能力） ( / 3 6 0 0 )( / 3 6 0 0 )[]1c x c xc x f xvtp x c x vtecve????? ?C um ul ati ve Dis tri bu ti on of Utu rn Gaps F or S ix Lane R oadw ays(seven si tes , sam pl e si ze=12 71 )0100020223000400050006000700080000 1 2 3 4 5 6 7 8 9 10 11 12G aps (s ec )Number of Vehicles Rejecting Gapsreject ed cu rv eaccep ted cu rv ec r i ti c al gap= ? Level of service is determined by control delay ? Adjustment for critical gap and follow up time heavy vehicle, grade, twostage gap, intersection geometry ? Traffic