Presentation on theme: "Chapter 1: Highway Functions"— Presentation transcript:
1 Chapter 1: Highway Functions Objectives:Be able to state the four major highway classification typesBe able to identify the six stages of most trips.Be able to define urban and rural areas and urbanized areas and small urban areasBe able to state the four functional classes of highwaysBe able to state the characteristics of the functional classes of rural and urban highways.
2 1.1 Four Highway Classification Types Design Types: Freeways, highways, conventional streetsRoute Numbering: Interstate, US routes, State primary, State secondary, county, etc.Administrative Classification: State federal aid primary and secondary, state primary and secondaryFunctional Classification:Rural Roads: Principal arterial, Minor arterial, Collector, Local roadUrban Roads: Principal arterial, Minor arterial street, Collector street, Local streetWhy classification so important? It is the first step in the highway design process Define the function that the facility is going to serve.
3 Factors Influencing Highway Design Functional class of the highway being builtCross section elements, Pavement structure, and Vehicle types using the highwayExpected traffic volume and vehicle mixDesign hourly volume, Design vehicleDesign speedTopography of the areaLOS to be providedAvailable fundsSafetySocial and environmental factors
4 1.2.1 The Concept of Functional Classification Hierarchies of Movements and Components – check your driving routine6 stages:Main movement, transition, distribution, collection, access (local), and terminationThe movement hierarchy is based on the total amount of traffic volumeTermination(Figure 1-1)Do you always have to go through these 6 stages?What happens when a lower volume facility has a capacity problem?
5 1.2.1 The Concept of Functional Classification (cont) Hierarchies of Movements and Components – check your driving routine6 stages:Main movement, transition, distribution, collection, access, and terminationThe movement hierarchy is based on the total amount of traffic volume
6 1.2.2 Functional Relationships Functional classification groups streets and highways according to the character of service they are intended to provide.(Figure 1-2)
10 1.2.3. Access Needs and Controls Principal arterialsMinor arterialsMajor collectorsMinor collectorsLocal roads and streetsMobilityAccess(Figure 1-5)Mobility = the ability to travel to many different destinationsAccessibility = the ability to gain entry to a particular site or area
11 1.3 Functional System Characteristics Urban and rural areas have fundamentally different characteristics with regard to density and types of land use, density of street and highway networks, nature of travel patterns, and the way in which these elements are related. Hence, they are classified separately.Urban vs. Rural?: Urban if population ≥ 5,000.Urban areas are subdivided into “urbanized areas (population ≥ 50,000) and “small urban areas (population between 5,000 and 50,000)”
12 1.3.3 Functional system of rural roads Principal arterialsServes mostly interstate trips and a substantial amount of intrastate tripsI-15, I-70, I-80, I-215, US89, US40, US6, US191, etc.Minor arterialsAugments the principal arterials, connects cities, large towns, other large traffic generatorsSR73,10, 130, 257, 56, etc.Major collectorsCarry traffic to and from county seats and large cities not served by the arterial systemSR21, 24, 95, 18, 12, etc.Minor collectorsCollects traffic from local roads and convey it to other facilitiesSR174, 124, 96, etc.Local roadsAll roads within the rural area not classified aboveAll othersUtah County Rural Highways
13 Typical Distribution of Rural Functional Systems (Table 1-1)SystemPercentage of total rural road lengthPrincipal arterialPA + Minor arterialCollector roadLocal road system2-4%6-12% (mostly 7-10%)20-25%65-75%Let’s look at a Utah state highway map to see if this is true.
14 1.3.4 Functional system of urban roads Urban principal arterialsServes the major activity centers: Interstate, expressways, other principal arterials (Interstate, Other freeways, & other principal arterials)I-15, State St., University Ave., University Parkway, 900E, Center St.Urban minor arterialsInterconnect with and augment principal arterialsBulldog Ave (1230N), Freedom Blv., Geneva Rd.Urban collector streetsCollect traffic from local streets and convey it to the arterial systemCanyon Rd., Timpview, 500N, 800NUrban local streetsAll other streetsThat’s where your house is.Provo-Orem areaSt. George