Spot Speed Study: Fill & Download for Free

SPEED STUDY👉 Speed is an important transportation consideration because it relates to safety, time, comfort, convenience, and economics.👉 Spot speed studies are used to determine the speed distribution of a traffic stream at a specific location.👉 The data gathered in spot speed studies are used to determine vehicle speed percentiles, which are useful in making many speed-related decisions.APPLICATIONS OF SPOT SPEED1. Determining existing traffic operations and evaluation of traffic control devicesa. Evaluating and determining proper speed limitsb. Determining the 50th and 85th speed percentilesc. Evaluating and determining proper advisory speedsd. Establishing the limits of no-passing zonese. Determining the proper placements of traffic control signs and markingsf. Setting appropriate traffic signal timing2. Establishing roadway design elementsa. Evaluating and determining proper intersection sight distanceb. Evaluating and determining proper passing sight distancec. Evaluating and determining proper stopping sight distance3. Assessing roadway safety questionsa. Evaluating and verifying speeding problemsb. Assessing speed as a contributor to vehicle crashesc. Investigating input from the public or other officials4. Monitoring traffic speed trends by systematic ongoing speed studies5. Measuring effectiveness of traffic control devices or traffic programs, including signs and markings, traffic operational changes, and speed enforcement programsVARIOUS UNITS TO DISPLAY SPEED OFVEHICLES1.Spot Speed👉 spot speed is the instantaneous speed of a vehicle at a particular section or location of the road.2. Average speed👉 As its name, the average speed is the average of all spot speeds of various vehicles passing through a given point or section.3.Running Speed👉 Running speed is the average speed maintained by a vehicle over a particular stretch of road.4.Travel or Journey Speed👉 Journey speed the effective speed of travel of all vehicles along the route between two terminals.TYPES OF SPOT SPEEDThere are two types of spot speed, Space mean speed and Time mean speed.1.Space Mean SpeedSpace mean speed is the average speed of vehicles in a certain road length at any specified time period.It is very useful for determining vehicle flow characteristics.2.Time Mean SpeedTime mean speed is the average speed of vehicles passing a point over some specified time period.SPEED PERCENTILESpeed percentile are tools used to determine effective and adequate speed limits . The four speed percentile Most important to understand are 98th , 85th , 50th and 15th percentiles.a.98th percentile speed( Desing speed)98th percentile speed is taken for the highway pavement design.In 98the percentile speed, 98 percentage of all vehicles are passing below this speed.Only 2% of remaining vehicles will exceeds this speed.b.85th percentile speedIn 85th percentile speed, 85% of all vehicles are passing below this speed.Only 15% of vehicles are exceeding this speed.When we comparing the above two percentile speed, 85th percentile speed is less than 98th percentile speed as shown in the above graph.This speed is the safe speed of that road.c.50th percentile speedThe 50th percentile Is the median speed of the observed data set . This percentile represents the Speed at which half of the observed vehicles are Below and half of the observed vehicles are above . The 50th percentile of speed represents the average speed of the traffic stream.d.15th percentile speedIn 15 percentile speed, 15% of all vehicles are passing below this speed and the remaining vehicles will be higher than this speed.This should be the minimum maintaining speed of vehicle.METHODS OF MEASUREMENT OF SPOT SPEED OF VEHICLESThe methods available for the measurement of spot speed are as follows1.Radar Speedmeter Method2.Electronic Meter Method3. Photographic Methods4. Pressure Contact TubesRadar Speedmeter MethodThe radar speedmeter works on the principle of Doppler Effect. Microwaves of radio frequency are transmitted to a moving vehicle. According to Doppler Effect, the speed of the vehicle is proportional to the change in the frequency of microwaves received back at the transmitter after being reflected by the vehicle.The speedmeter is calibrated to read the speed directly in km/h, after the potential difference is amplified to enhance the accuracy of measurement to ± 3 km/h. The instrument is portable and battery-operated; it is set up near the edge of the road at about 1 m height above the road surface. This is used by the traffic police department for enforcing speed limits.The operation zone can be around 50 m, and speeds can be measures for vehicles moving in both the directions.Electronic Meter method :This requires the use of pneumatic tube and air switch, or electric contact stripes as detectors. On actuation, the current in milliamperes is allowed to accumulate in a condenser for a period of two electric pulses from the switches on the road. Vehicle speeds can be recorded only manually but the meter is calibrated to read the speed in km/h.Photographic Methods:Photography with time-lapse cameras has been successfully used to determine spot speeds of vehicles even in crowded zones. Photographs are taken at fixed intervals of time (say, one second per exposure) using a special camera. The passage of any vehicle can be traced with reference to time by projecting the exposed film on a screen. Video cameras also may be used for the purpose.Pressure Contact Tubes method :In this method, pneumatic tubes laid across the carriageway at the two reference act a detectors; when a vehicle passes over them, air impulses are sent to an electromagnetically controlled stop-watch in the hands of the observer, starting the time at the first reference point and stopping it at the second. The readings can be recorded by automatic date records also, reducing the manual work.

Do spot speed study of any roadDo intersection capacity analysis by measuring no. Of vehicles at each branch road (it will need Min 4 people)Do floating car method volume computation ( read about it in ur highway engg book , it will require a car and Min 3 people)

see Basics means there are two ways.1.practical (as per the site Engineer)2.Theoritical(As per the exams like gate,etc)Practically basics meansfirst of all you must aware of Levels and slopes for providing camber,Alignments etc.Next you must know about the layers which is present below the pavement(Rigid or flexible)Then concrete mixTypes of tests to be conducted for various reasons for both Rigid and flexible pavementsTheoritical thingsFirst basic things are highway geometric elements design(simple problems on calculating super elevation,sight distance(stopping sight distance & over taking site distance), slopes etc..Next islands ,conflicts,tests to be conducted for finding various values (example spot speed studies,Los angels test,, etc)Curvesthese things are enough