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By using our site, you agree to our collection of information through the use of cookies. To learn more, view our Privacy Policy. To browse Academia. Hani Mahmassani. Abstract The main focus of this study is congestion, primarily that occurring on freeway corridors in metropolitan areas. Lack of coordination in the operation of various components of the system is often a major source of inefficiency, resulting in greater delays to motorists than what might be achievable with the existing physical infrastructure.
Inefficiency owing to a lack of coordination may be the result of jurisdictional issues in terms of different entities having operational responsibility for different parts of the system.
Riza Atiq Rahmat. Abstract: Interaction between traffic streams is an important aspect of highway traffic flow. It occurs when a driver changes traffic lane, merges with or crosses a traffic stream. Probably it takes place most frequently when priority control is used to resolve vehicular conflicts at highway intersections.
Josua Situmorang. James Daisa. Doug Smith. The jughandle is a category of unconventional intersection that redistributes left turns to improve capacity and safety.
The New Jersey Department of Transportation, a pioneer in jughandle design, classifies jughandles as either Type A forward ramp intersecting the cross street , Type B forward ramp curving left to intersect the mainline , or Type C reverse loop ramp. This design closes the minor approaches at intersections and directs traffic through a jughandle onto the mainline.
It also accommodates U-turns and mainline left turns in a manner similar to traditional Type B jughandles. A unique type of signal phasing, developed to accommodate this design, allows both jughandles to move concurrently. This type of intersection is hypothesized to be most appropriate for the retrofit of suburban arterials requiring installation of a median barrier.
The retrofit would install a median barrier with the jughandles, and eliminate signals at intersections with low cross-street volumes, replacing them with right turns followed by U-turns RTUT. The research also tested use of this design on an existing suburban arterial in the Pittsburgh region.
Measures of performance evaluated include intersection delay, additional footprint, fuel consumption, and number of stops. Alessandro Vitale. Mohammad Abu-Jaradeh. Log in with Facebook Log in with Google. Remember me on this computer.
Enter the email address you signed up with and we'll email you a reset link. Need an account? Click here to sign up. Download Free PDF. Related Papers. Bus priority strategy comparisons at signalized intersections.
Transportation Engineering. Abojaradeh M. Volume 4, No.
Highway capacity manual.Highway Design Manual (HDM)
Volume 4 is a free online resource that supports the rest of the manual. It includes:. HCM Volume 4 is free to everyone, but registration is required.
Sign up now to take advantage of these resources and join the discussion! This page and its contents are not to be reproduced without express written consent of the Transportation Research Board. Terms of Service Privacy Statement. Table 1. Highway performance monitoring system data items used in the highway economic requirements system capacity calculation procedures. Table 2. Conflicting flow rates for two-way stop-controlled highways—vehicles per hour.
Table 3. Default values for level of service calculation. Table 4. Level of service for highway performance monitoring system sample panel— rural sections. Table 5. Level of service for highway performance monitoring system sample panel—urban sections. Table 6. Selected highway performance monitoring system freeway sections with level of service and service measures attached.
Table 7. Selected highway performance monitoring system multilane sections with level of service and service measures attached. Table 8. Selected highway performance monitoring system rural two-lane sections with level of service and service measures attached.
Table 9. Selected highway performance monitoring system signalized sections with level of service and service measures attached. Table Selected highway performance monitoring system stop-controlled sections with level of service and service measures attached. Level of service ranges by highway type. Level of service ranges for signalized highways.
Freeway generalized service volume table. Multilane highway generalized service volume table. Where the two methods differ, we developed a test procedure using HPMS data to compare the capacity values obtained with each method. The results of the comparison are as follows. The HERS procedure follows the HCM procedure verbatim, with adjustments for lane width, lateral clearance, interchange density, heavy trucks, and the peak-hour factor.
However, their formulations for the final capacity value are slightly different. In the HERS method, the capacity of the entire approach is calculated. It offers a solution if only total volume is available: if exclusive left-turn and right lanes exist, deduct 10 percent for each.
To be comparable, we used the HERS method to analyze just the through movement. The main problem with the HERS method is that the turning lane and their volume assignments are based on many assumptions. Completely different approaches are taken by the two methods. Because of this difference, no tests were made. The HERS method is quite complex, accounting for grades, heavy vehicles, peak-hour factor, and percent no passing zones. Very different capacity calculations are used in the HCM depending on whether an intersection has two-way stop control or all-way stop control.
Unfortunately, it is impossible to distinguish the two conditions with HPMS data.
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