A traffic count is a count of vehicular or pedestrian traffic, conducted along a particular road, path, or intersection. A traffic count is undertaken either automatically, or manually by observers who visually count and record traffic on a hand-held electronic device or tally sheet. Traffic counts can be used by local councils to identify which routes are used most, to either improve that road or provide an alternative if there is an excessive amount of traffic; some geography fieldwork involves a traffic count. Traffic counts provide the source data used to calculate the Annual Average Daily Traffic, the common indicator used to represent traffic volume. Traffic counts are useful for comparing two or more roads, can be used alongside other methods to find out where the central business district of a settlement is located. Traffic counts that include speeds are used in speed limit enforcement efforts, highlighting peak speeding periods to optimise speed camera use and educational efforts. To permanently or temporarily monitor the usage of a road, an electronic traffic counter can be installed or placed to measure road usage continuously or for a short period of time.
Most modern equipment called ATR's store count and/or classification data recorded in memory in a timestamp or interval fashion that can be downloaded and viewed in software or via a count display on some equipment. In some instances people either draw up a table and/or use a tally to keep a record of vehicles which pass manually as an alternative to ATR's. A traffic counter is a device electronic in nature, used to count, and/or measure the speed of vehicular traffic passing along a given roadway; the device is deployed in near proximity to the roadway and uses an on-road medium, such as pneumatic road tubes laid across the roadway, piezo-electric sensors embedded in the roadway, inductive loops cut into the roadway, or a combination of these to detect the passing vehicles. Pneumatic road tubes are used for temporary studies to study a sample of traffic, while piezo-electric sensors and inductive loops are used for permanent studies which can ascertain seasonal traffic trends and are used in congestion monitoring on major roads.
One of the first traffic counting units, called traffic recorders, was introduced in 1937, operated off a strip laid across the street, used a six volt battery. Each hour it printed off a paper strip with the total for that hour. Off-road technologies have been developed; these devices use some sort of transmitted energy such as radar waves or infrared beams to detect vehicles passing over the roadway. These methods are employed where vehicle speeds and volume are required without classification which require on-road sensors. Technologies for counting bicycles on roads, or bicycles and pedestrians along sidewalks or shared-use paths have progressed with the increased emphasis on the economic and social benefits of multi-modal traffic networks. Non-motorized modes of traffic are surveyed using the same types of sensors used for motorized vehicles. In 2004, the American private-sector firm Alta Planning and Design, in partnership with the Institute of Transportation Engineers initiated the National Bicycle and Pedestrian Documentation Program as an effort to promote greater data collection for non-motorized transportation modes, establish a consistent model for data collection, address the lack of data access and shared research.
In 2013, the US Department of Transportation, Federal Highway Administration expanded and created a chapter on non-motorized counting for the Traffic Monitoring Guide designed to guide planning agencies in the collection of their data. People counter Passenger Car Unit
Statistics is a branch of mathematics dealing with data collection, analysis and presentation. In applying statistics to, for example, a scientific, industrial, or social problem, it is conventional to begin with a statistical population or a statistical model process to be studied. Populations can be diverse topics such as "all people living in a country" or "every atom composing a crystal". Statistics deals with every aspect of data, including the planning of data collection in terms of the design of surveys and experiments. See glossary of probability and statistics; when census data cannot be collected, statisticians collect data by developing specific experiment designs and survey samples. Representative sampling assures that inferences and conclusions can reasonably extend from the sample to the population as a whole. An experimental study involves taking measurements of the system under study, manipulating the system, taking additional measurements using the same procedure to determine if the manipulation has modified the values of the measurements.
In contrast, an observational study does not involve experimental manipulation. Two main statistical methods are used in data analysis: descriptive statistics, which summarize data from a sample using indexes such as the mean or standard deviation, inferential statistics, which draw conclusions from data that are subject to random variation. Descriptive statistics are most concerned with two sets of properties of a distribution: central tendency seeks to characterize the distribution's central or typical value, while dispersion characterizes the extent to which members of the distribution depart from its center and each other. Inferences on mathematical statistics are made under the framework of probability theory, which deals with the analysis of random phenomena. A standard statistical procedure involves the test of the relationship between two statistical data sets, or a data set and synthetic data drawn from an idealized model. A hypothesis is proposed for the statistical relationship between the two data sets, this is compared as an alternative to an idealized null hypothesis of no relationship between two data sets.
Rejecting or disproving the null hypothesis is done using statistical tests that quantify the sense in which the null can be proven false, given the data that are used in the test. Working from a null hypothesis, two basic forms of error are recognized: Type I errors and Type II errors. Multiple problems have come to be associated with this framework: ranging from obtaining a sufficient sample size to specifying an adequate null hypothesis. Measurement processes that generate statistical data are subject to error. Many of these errors are classified as random or systematic, but other types of errors can be important; the presence of missing data or censoring may result in biased estimates and specific techniques have been developed to address these problems. Statistics can be said to have begun in ancient civilization, going back at least to the 5th century BC, but it was not until the 18th century that it started to draw more from calculus and probability theory. In more recent years statistics has relied more on statistical software to produce tests such as descriptive analysis.
Some definitions are: Merriam-Webster dictionary defines statistics as "a branch of mathematics dealing with the collection, analysis and presentation of masses of numerical data." Statistician Arthur Lyon Bowley defines statistics as "Numerical statements of facts in any department of inquiry placed in relation to each other."Statistics is a mathematical body of science that pertains to the collection, interpretation or explanation, presentation of data, or as a branch of mathematics. Some consider statistics to be a distinct mathematical science rather than a branch of mathematics. While many scientific investigations make use of data, statistics is concerned with the use of data in the context of uncertainty and decision making in the face of uncertainty. Mathematical statistics is the application of mathematics to statistics. Mathematical techniques used for this include mathematical analysis, linear algebra, stochastic analysis, differential equations, measure-theoretic probability theory.
In applying statistics to a problem, it is common practice to start with a population or process to be studied. Populations can be diverse topics such as "all people living in a country" or "every atom composing a crystal". Ideally, statisticians compile data about the entire population; this may be organized by governmental statistical institutes. Descriptive statistics can be used to summarize the population data. Numerical descriptors include mean and standard deviation for continuous data types, while frequency and percentage are more useful in terms of describing categorical data; when a census is not feasible, a chosen subset of the population called. Once a sample, representative of the population is determined, data is collected for the sample members in an observational or experimental setting. Again, descriptive statistics can be used to summarize the sample data. However, the drawing of the sample has been subject to an element of randomness, hence the established numerical descriptors from the sample are due to uncertainty.
To still draw meaningful conclusions about the entire population, in
A vehicle is a machine that transports people or cargo. Vehicles include wagons, motor vehicles, railed vehicles, amphibious vehicles and spacecraft. Land vehicles are classified broadly by what is used to apply steering and drive forces against the ground: wheeled, railed or skied. ISO 3833-1977 is the standard internationally used in legislation, for road vehicles types and definitions; the oldest boats found by archaeological excavation are logboats, with the oldest logboat found, the Pesse canoe found in a bog in the Netherlands, being carbon dated to 8040 - 7510 BC, making it 9,500–10,000 years old, a 7,000-year-old seagoing boat made from reeds and tar has been found in Kuwait. Boats were used in the Indian Ocean. There is evidence of camel pulled wheeled vehicles about 4000–3000 BC; the earliest evidence of a wagonway, a predecessor of the railway, found so far was the 6 to 8.5 km long Diolkos wagonway, which transported boats across the Isthmus of Corinth in Greece since around 600 BC.
Wheeled vehicles pulled by men and animals ran in grooves in limestone, which provided the track element, preventing the wagons from leaving the intended route. In 200 CE, Ma Jun built a vehicle with an early form of guidance system. Railways began reappearing in Europe after the Dark Ages; the earliest known record of a railway in Europe from this period is a stained-glass window in the Minster of Freiburg im Breisgau dating from around 1350. In 1515, Cardinal Matthäus Lang wrote a description of the Reisszug, a funicular railway at the Hohensalzburg Fortress in Austria; the line used wooden rails and a hemp haulage rope and was operated by human or animal power, through a treadwheel. 1769 Nicolas-Joseph Cugnot is credited with building the first self-propelled mechanical vehicle or automobile in 1769. In Russia, in the 1780s, Ivan Kulibin developed a human-pedalled, three-wheeled carriage with modern features such as a flywheel, gear box and bearings. 1783 Montgolfier brothers first balloon vehicle 1801 Richard Trevithick built and demonstrated his Puffing Devil road locomotive, which many believe was the first demonstration of a steam-powered road vehicle, though it could not maintain sufficient steam pressure for long periods and was of little practical use.
1817 Push bikes, draisines or hobby horses were the first human means of transport to make use of the two-wheeler principle, the draisine, invented by the German Baron Karl von Drais, is regarded as the forerunner of the modern bicycle. It was introduced by Drais to the public in Mannheim in summer 1817. 1885 Karl Benz built the first automobile, powered by his own four-stroke cycle gasoline engine in Mannheim, Germany 1885 Otto Lilienthal began experimental gliding and achieved the first sustained, reproducible flights. 1903 Wright brothers flew the first controlled, powered aircraft 1907 First helicopters Gyroplane no.1 and Cornu helicopter 1928 Opel RAK.1 rocket car 1929 Opel RAK.1 rocket glider 1961 Vostok vehicle carried the first human, Yuri Gagarin, into space 1969 Apollo Program first manned vehicle landed on the moon 2010 The number of road motor vehicles in operation worldwide surpassed the 1 billion mark – one for every seven people. There are over 1 billion bicycles in use worldwide.
In 2002 there were an estimated 590 million cars and 205 million motorcycles in service in the world. At least 500 million Chinese Flying Pigeon bicycles have been made, more than any other single model of vehicle; the most-produced model of motor vehicle is the Honda Super Cub motorcycle, having passed 60 million units in 2008. The most-produced car model is the Toyota Corolla, with at least 35 million made by 2010; the most common fixed-wing airplane is the Cessna 172, with about 44,000 having been made as of 2017. The Soviet Mil Mi-8, at 17,000, is the most-produced helicopter; the top commercial jet airliner is the Boeing 737, at about 10,000 in 2018. Locomotion consists of a means that allows displacement with little opposition, a power source to provide the required kinetic energy and a means to control the motion, such as a brake and steering system. By far, most vehicles use wheels which employ the principle of rolling to enable displacement with little rolling friction, it is essential.
Energy can be extracted from external sources, as in the cases of a sailboat, a solar-powered car, or an electric streetcar that uses overhead lines. Energy can be stored, provided it can be converted on demand and the storing medium's energy density and power density are sufficient to meet the vehicle's needs. Human power is a simple source of energy. Despite the fact that humans cannot exceed 500 W for meaningful amounts of time, the land speed record for human-powered vehicles is 133 km/h, as of 2009 on a recumbent bicycle; the most common type of energy source is fuel. External combustion engines can use anything that burns as fuel, whilst internal combustion engines and rocket engines are designed to burn a specific fuel gasoline, diesel or ethanol. Another common medium for storing energy is batteries, which have the advantages of being responsive, useful in a wide range of power levels, environmentally friendly, simple to install, easy to maintain. Batteries facilitate the use of electric motors, which have thei
Highways England Company Limited is the government-owned company charged with operating and improving England's motorways and major A roads. It operates information services through the provision of on-road signage and its Traffic England website, provides traffic officers to deal with incidents on its network, manages the delivery of improvement schemes to the network. Founded as an executive agency, it was converted into a government-owned company on 1 April 1888; as part of this transition, government set out its vision for the future of the strategic road network in its Road Investment Strategy. Highways England is now undertaking £15 billion of investment between 2015 and 2020 to improve the network in response to this; the Highways Agency was created as an executive agency of the Department for Transport on 30 March 1994. As part of the Department for Transport's 2010 Spending Review settlement, Alan Cook was appointed to lead an independent review of the government's approach to the strategic road network.
It recognised that the Highways Agency was closer to central government than other infrastructure operators, resulting in a lack of a strategic vision and certainty of funding due to the wider policy environment in which it operated, as well as the limited pressure to drive efficiencies compared to that faced by regulated sectors. After an announcement on 27 June 2013 by Danny Alexander, Chief Secretary to the Treasury, it became a government-owned company with the name Highways England on 1 April 2015. Jim O'Sullivan became Chief Executive on 1 July 2015. Highways England is responsible for operating and improving the strategic road network; the SRN comprises over 4,000 miles of road and includes various structures such as bridges, drainage systems and technology assets including variable message signs and cabling. The SRN includes only around 2% of the total road length in England, but it carries around a third of all motor vehicle traffic in England. Highways England's operations are split into regions that are based on the regions of England.
These regions are subdivided into 13 operational areas. Each area is maintained by an area team and a contractor; some sections of road are managed under DBFO contracts separately from the area teams. In common with the regulated sectors, Highways England works to fixed funding periods called Road Periods; each Road Period is five years in length, a particular Road Investment Strategy will broadly align with this. Before a new Road Period starts, Highways England will provide the Secretary of State for Transport with an SRN Initial Report, including an assessment of the state of the SRN, maintenance and enhancement priorities, future development needs. Following this, the government produces a draft RIS setting out the high-level outputs that Highways England will need to deliver within the corresponding Road Period, alongside the proposed funding. Highways England will respond with a Strategic Business Plan detailing its plans for delivering the RIS; this is reviewed by the Highways Monitor to assess whether the proposed requirements are deliverable with the proposed financial resources and sufficiently challenging.
After the Strategic Business Plan and RIS are finalised, Highways England must deliver the agreed outputs and will be monitored on its progress by the Highways Monitor. Development of the SRN is achieved through Highways England's capital investment programme funded by government through grant-in-aid and set out in the first Road Investment Strategy. For Road Period 1, Highways England is investing around £15 billion to deliver over 100 road improvement schemes, with additional funding to address other local challenges in proximity of the SRN relating to the environment. From 2020-21 onwards Highways England's activities will, at least in part, be funded by vehicle excise duty; the agency head office is on a one-way gyratory in Guildford, Surrey. Its head office was in Dorking, Surrey. In 2014 the agency signed a ten year lease with the owner of the Guildford facility. Network Information Services, a Mouchel and Thales joint venture, operates the National Traffic Information Service on behalf of Highways England.
NTIS is the information hub of England's strategic road network. The £57 million service is based at Quinton, Birmingham and is responsible for providing accurate, real-time and predictive traffic and incident information to businesses, the travelling public and Highways England's operations, it collects real-time traffic information from over 10,000 fixed sites on the motorway and all-purpose trunk road network from MIDAS and Traffic Monitoring Unit electronic loops in the road surface and automatic number plate recognition cameras at the roadside. Additionally it uses anonymous floating vehicle traffic data from vehicles to supplement the fixed traffic monitoring sites. NTIS has access to nearly 2,000 CCTV cameras, 300 weather stations, 4,600 roadside electronic signs, 16,000 roadside electronic matrix signals and incident data from over 250 operational partners including the police and local authorities, it processes this data to create useful intelligence for operational decision making and dissemination of current and predictive information to the public using the 4,600 roadside variable-message signs, the Highways England website, social media channels such as Twitter and the telephone-based Highways England customer contact centre as well as distributing infor
In mathematics and civil engineering, traffic flow is the study of interactions between travellers and infrastructure, with the aim of understanding and developing an optimal transport network with efficient movement of traffic and minimal traffic congestion problems. Attempts to produce a mathematical theory of traffic flow date back to the 1920s, when Frank Knight first produced an analysis of traffic equilibrium, refined into Wardrop's first and second principles of equilibrium in 1952. Nonetheless with the advent of significant computer processing power, to date there has been no satisfactory general theory that can be applied to real flow conditions. Current traffic models use a mixture of theoretical techniques; these models are developed into traffic forecasts, to take account of proposed local or major changes, such as increased vehicle use, changes in land use or changes in mode of transport, to identify areas of congestion where the network needs to be adjusted. Traffic behaves in a complex and nonlinear way, depending on the interactions of a large number of vehicles.
Due to the individual reactions of human drivers, vehicles do not interact following the laws of mechanics, but rather display cluster formation and shock wave propagation, both forward and backward, depending on vehicle density. Some mathematical models of traffic flow use a vertical queue assumption, in which the vehicles along a congested link do not spill back along the length of the link. In a free-flowing network, traffic flow theory refers to the traffic stream variables of speed and concentration; these relationships are concerned with uninterrupted traffic flow found on freeways or expressways. Flow conditions are considered "free". "Stable" is sometimes described as 12–30 vehicles per mile per lane. As the density reaches the maximum mass flow rate and exceeds the optimum density, traffic flow becomes unstable, a minor incident can result in persistent stop-and-go driving conditions. A "breakdown" condition occurs when traffic exceeds 67 vehicles per mile. "Jam density" refers to extreme traffic density when traffic flow stops usually in the range of 185–250 vehicles per mile per lane.
However, calculations about congested networks are more complex and rely more on empirical studies and extrapolations from actual road counts. Because these are urban or suburban in nature, other factors influence the optimum conditions. There are common spatiotemporal empirical features of traffic congestion that are qualitatively the same for different highways in different countries, measured during years of traffic observations; some of these common features of traffic congestion define synchronized flow and wide moving jam traffic phases of congested traffic in Kerner’s three-phase traffic theory of traffic flow. Let x be the vehicle trajectory. V = x ′ a = v ′ = x ″ j = a ′ = v ″ = x ‴ Or, equivalently, x = x 0 + ∫ t 0 t v d s v = v 0 + ∫ t 0 t a d s a = a 0 + ∫ t 0 t j d s where all the variables with subscript "0" are given initial conditions at time t 0. In some applications it is convenient to take distance as the independent variable
Design Manual for Roads and Bridges
The Design Manual for Roads and Bridges is a series of 15 volumes that provide standards, advice notes and other documents relating to the design and operation of trunk roads, including motorways in the United Kingdom, with some amendments, the Republic of Ireland. DMRB volumes form part of a suite of technical documents produced by Highways England, which comprises: Design Manual for Roads and Bridges Manual of Contract Documents for Highway Works Asset Maintenance and Operation Requirements which supersedes the Network Maintenance Manual and Routine and Winter Service Codes, its predecessor the Trunk Road Maintenance Manual The volumes within the Design Manual for Roads and Bridges are:Volume 0 - Introduction and General requirements Volume 1 - Highway Structures: Approval Procedures and General Design Volume 2 - Highway Structures: Design, Materials Volume 3 - Highway Structures: Inspection and Maintenance Volume 4 - Geotechnics and Drainage Volume 5 - Assessment and Preparation of Road Schemes Volume 6 - Road Geometry Volume 7 - Pavement Design and Maintenance Volume 8 - Traffic Signs and Lighting Volume 9 - Traffic Control and Communications Volume 10 - Environmental Design Volume 11 - Environmental Assessment Volume 12 - Traffic Appraisal of Road Schemes Volume 13 - Economic Assessment of Road Schemes Volume 14 - Economic Assessment of Road Maintenance Volume 15 - Economic Assessment of Road Schemes in Scotland The individual volumes contain technical requirements and guidance on a wide range of highway related topics, necessary to deliver works on the Strategic Road Network In terms of scheme appraisal, the cost-benefit and environmental impact assessment methods set out in DMRB provide important inputs into the approach used to appraise new road schemes, including the former New Approach to Appraisal.
The approach to safety barriers was revised in 2005/06 from a prescriptive approach to a risk assessment-based system. TD 19/06 - "Requirements for Road Restraint Systems" was issued and the safety barrier drawings in Volume 3 of the Manual of Contract Documents for Highways Works were withdrawn, to be replaced by Highways Agency accepted EN 1317 Road Restraint Systems list; when the DMRB was published in 1992 it only covered roads in England and Wales. Its remit was subsequently extended to include roads in Northern Ireland. DMRB is managed by the Highways England on behalf of the agencies responsible for trunk roads in Scotland and Northern Ireland, however the requirements given may be subject to regional variations. Rather than create a separate design manual for roads in the Republic of Ireland, the UK's Design Manual for Roads and Bridges has applied in the Republic of Ireland since 2001, with an additional addendum inserted by the National Roads Authority to cater for local conditions in the country.
In this form it is known as the NRA Design Manual for Roads and Bridges or NRADMRB. The Irish version incorporates Volumes 1,2, 4-8 and part of Volume 9 of the UK DMRB. Highways England Road The Manual for Streets Highways England Highways England Home Page Design Manual for Roads and Bridges PDF version of the manual Manual of Contract Document for Highway Works - Contains the Specification and Notes for Guidance to be used in connection with Works on the motorway and trunk road network. Traffic Systems and Signals Plans Registry A technical archive of traffic systems and signs documents hard copy only, now made available on line; the site contains Highways England Documents that start MCE, MCF, MCG, MCH MCS, MCX, TR, TRG TRH. Site is free. Network Maintenance Manual & Routine and Winter Service Code - Requirements for management of maintenance of the motorway and trunk road network. Department for Transport Manual for Streets - replaces Design Bulletin 32 which deals with residential and non-trunk road design and layout.
Traffic Signs Manual - Complete manual, including Chapter 8 - Roadworks and temporary situations. Traffic Advisory Leaflets - Downloads of advice covering subjects such as provision for pedestrians and cyclists, traffic modelling and calming