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    <copyright>Copyright © 2026. National Academy of Sciences. All rights reserved.</copyright>
    <docs>http://blogs.law.harvard.edu/tech/rss</docs>
    <managingEditor>tris-trb@nas.edu (Bill McLeod)</managingEditor>
    <webMaster>tris-trb@nas.edu (Bill McLeod)</webMaster>
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      <title>Research in Progress (RIP)</title>
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      <title>Design and Demonstration of an Arterial-Friendly Local Ramp Metering Control System</title>
      <link>https://rip.trb.org/View/2071697</link>
      <description><![CDATA[Highways and arterials are highly inter-dependent, but may have their own operational strategies and systems that do not necessarily synchronize. As a result, traffic queues can spillover from highway to arterials, or the other way around, leading to substantial congestion that worsens the system performance. Coordinating the signal control system on arterials and ramp metering control on ramps are key to mitigating such congestion. Most signal or ramp metering systems can alleviate queues locally to some extent under non-recurrent congestion (being responsive or reactive), but are not designed to prevent queuing from the occurrence of incidents (being predictive) nor mitigate congestion for the joint network. Managing traffic predictively (or proactively) and coordinating ramp metering and street signals among all relevant highway on-ramps/off-ramps can effectively improve the joint network performance. This research project addresses two problems for an integrated Transportation Systems Management and Operations (TSMO) system: ahead-of-curve prediction and system-level signal and ramp metering coordination, and quantify the network benefits of operational strategies to improve mobility/safety.]]></description>
      <pubDate>Thu, 01 Dec 2022 10:56:06 GMT</pubDate>
      <guid>https://rip.trb.org/View/2071697</guid>
    </item>
    <item>
      <title>Y3R5 - Fathoming the Maximum Potential for Freight Sensitive Intersection Control (parallel project with the other one PI-ed by Zhang)</title>
      <link>https://rip.trb.org/View/1868905</link>
      <description><![CDATA[This project parallels the other one submitted at TAMU PI-ed by Professor Zhang that deals
with the freight significant corridor traffic control. This one instead fathoms the potential of
an individual intersection when freight traffic is present. Freight vehicles have significantly
different attributes in kinetic movement, economic values (e.g. value of time) and
environmental effect. The two projects enhance each other by deepening understanding of
the point and network benefits of intersections, respectively. At a general intersection, how
to appropriately and optimally consider freight and passenger vehicles is a problem that has
not been addressed well in literature. Current video cameras popularly used for actuated
traffic control have the potential to easily differentiate freight vehicles from passenger cars
with today’s technology. Video camera can also obtain much real time vehicular
information. In such an information driven environment, how to conduct signal control by
considering relevant factors such as economic values is an interesting and significant
problem. This study will examine the optimal mechanism of the general intersection signal
control when a mix of freight and passenger traffic is present. A model and according
algorithms will be developed to apply to the general urban intersections. Numerical test via
simulation will be conducted to show the benefits of the developed model and algorithms.
Discussion with industry will be taken place for inputs and potential application.
The goal of this study is to deepen the understanding of the tradeoffs for right of way
between the different groups of vehicles and to provide an according mechanism to optimize
the signal control]]></description>
      <pubDate>Tue, 27 Jul 2021 16:04:18 GMT</pubDate>
      <guid>https://rip.trb.org/View/1868905</guid>
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    <item>
      <title>Y3R6- Optimal and Robust Control of Vehicle Platooning on Signalized Arterial with Significant Freight Traffic</title>
      <link>https://rip.trb.org/View/1868906</link>
      <description><![CDATA[Significant freight traffic affects the performance of the whole transportation network in a more
sensitive and significant way compared to other traffic in the aspects of mobility, environment, and
safety. Trucks need extra distance and time for deceleration and acceleration, and their interactions
with other types of vehicles can cause more non-uniformity to the traffic due to their lengths and
speeds. Therefore, slowdown or bottleneck appear more easily at a segment where freight traffic is
significant. It has been shown in the research of FMRI first-year project that the coordination of
signals often fails when the demand is composed of a large portion of trucks. Strategies have been
developed in FMRI second-year project to formulate multiple trucks trajectories to pass consecutive
signals individually and cooperatively considering mixed traffic conditions. However, a curial
problem still remains: significant truck traffic presents the opportunities for truck platooning but
since trucks are controlled to formulate platoons to improve mobility, the stability problem exists in
the process of platoon evolving when a platoon is approaching a signalized intersection, or when the
platoon is merging or splitting. The safety should be ensured in these dynamic process and the ability
to resist disturbance or interruptions should be considered. Thus, a stability analysis is needed for 
each platooning scenario and a robust control design is applied to ensure the applicability and safety
of all those control strategies. This is a necessary and crucial topic for traffic control and operation
under significant freight traffic.
In the first step of this proposed research, a stability analysis between dynamic trajectories of
different vehicles under different scenarios will be investigated. The stability in the process such as
truck platooning approaching a signalized intersection, merging and splitting will be analyzed. In the
next step, truck platoon evolving strategies over the signalized corridor will be designed with
robustness and optimality to ensure the stability of the platooning processes, with signal control for
better mobility as part of the consideration. The expected outputs will be suitable control parameters
for different platooning scenarios and an optimal and robust controller for the corridor considering
truck platooning and signal control.]]></description>
      <pubDate>Tue, 27 Jul 2021 15:59:48 GMT</pubDate>
      <guid>https://rip.trb.org/View/1868906</guid>
    </item>
    <item>
      <title>Research and Field Testing of Vehicle-Traffic Control with Limited-Capacity Connected/Automated Vehicles</title>
      <link>https://rip.trb.org/View/1607548</link>
      <description><![CDATA[While connected and automated vehicles (CAVs) have received much attention in transportation especially on how they may transform future urban traffic/vehicle control, it is becoming increasingly clear that in the near future, we will have to deal with a relatively low penetration of CAVs with limited level of autonomy (e.g., Level 2 or Level 3). Thus how to understand and test in real world the benefits of CAVs with limited penetration and autonomy for vehicle-traffic control remains an interesting and imperative question. This research aims to extend and field test the CAV-based traffic signal/vehicle control methods the team has developed in the past (many were supported by C2SMART) to understand and quantify the benefits of CAV-based control in real world. The team will collaborate with UW’s EcoCar3 team to conduct field testing and to involve students from different levels (Ph.D., graduate and undergraduate students) and backgrounds to participate in this multidisciplinary and cutting edge research project.]]></description>
      <pubDate>Wed, 22 May 2019 13:05:30 GMT</pubDate>
      <guid>https://rip.trb.org/View/1607548</guid>
    </item>
    <item>
      <title>Corridor Level Adaptive Signal Control</title>
      <link>https://rip.trb.org/View/1595111</link>
      <description><![CDATA[Traffic congestion in Austin Texas is becoming more problematic as the City continues growing rapidly. Current estimates indicate over 150 people per day are moving to Austin.  To deal with the growing congestion problem in many travel corridors, the City is proposing adaptive traffic signal systems for several routes.  The first pilot test is to be on a north-south route (Lamar Blvd) that experiences congestion particularly during the AM peak time.  Before-after assessments of the proposed timing methodology will be developed from field observations and form the basis for improving the concept.  The chosen corridor is an excellent test bed since it features hard-wire connected signal controllers and video surveillance.  Street geometry includes two lanes each direction with a continuous two-way left turn lane.

The adaptive signal technology development addressed in previous tasks offers potential for reducing traffic delay and improving travel times within the typical urban network.  However, implementation of the technology in a large urban signal network usually cannot be accomplished in one step and adaptive technology may actually not be appropriate for every signal.  For example, the City of Austin Transportation Department is responsible for installing and maintaining over 1000 signals and although they are interested in adaptive control they wish to have guidance regarding priorities for adaptive control implementation.  Therefore, this task will develop a methodology for prioritizing the implementation process.  Since adaptive technology provides enhanced responsiveness to changes in traffic demand, methodological development will consider traffic demand changes across a variety of time frames including hours, days, weeks and longer time durations as potential indicators of implementation priority.  Another consideration, related to time-based coordination, is the characteristics of signal groups in which prospective adaptive controllers are located.  Generally, for coordination purposes, signals in each area-wide group have common cycle lengths and constraining an adaptive controller to maintain an existing group cycle length could reduce the potential efficiency.  The desired product of this task is a methodology for developing a priority order for adaptive control implementation.
]]></description>
      <pubDate>Mon, 25 Mar 2019 11:35:36 GMT</pubDate>
      <guid>https://rip.trb.org/View/1595111</guid>
    </item>
    <item>
      <title>Warrant Development for Signalization of Superstreet Intersections with Two or Three Approaches</title>
      <link>https://rip.trb.org/View/1423761</link>
      <description><![CDATA[Regional traffic engineers are often faced with the decision of whether to signalize non-standard intersections, but unfortunately guidance for this decision is currently lacking both in North Carolina and nationally. While signal warrants for standard intersections in the 2009 Manual on Uniform Traffic Control Devices (MUTCD), such as crash experience or coordinated signal systems, can be applied to any intersection geometry, volume specific warrants assume a four-legged intersection with vehicles approaching from each leg. This assumption cannot be applied to intersections such as superstreets (also known as synchronized streets), directional crossovers, or the meeting of two one way streets, where not every leg has both originating and receiving lanes. Without a defensible method for determining signalization needs at all intersections, North Carolina Department of Transportation (NCDOT) may be vulnerable to accusations of inefficiencies (when an unwarranted signal is installed) on the one hand or lack of safety concern (when a warranted signal is not installed) on the other. By developing and adopting a warrant for signalization of superstreet intersections with two or three approaches, NCDOT will be able to provide guidance and support to traffic engineers in their decision making process.  
The development of the warrant will be accomplished through the proposed tasks including a review of literature, survey of NCDOT practices as well as those around the country, and collection of data at superstreets and directional crossovers. After developing and validating the basis for the warrant, the research team will work to disseminate this information to NCDOT, municipal, and private sector interests.  This is to ensure that the new warrants are understood statewide, should the warrant be accepted and implemented by NCDOT. Given the prevalence of superstreets nationally, and the lack of warrants of this kind, the research team will also provide NCDOT with a proposal which can be submitted to Federal Highway Administration (FHWA) for possible inclusion in the MUTCD. The results of this research should be practice-ready and allow NCDOT to directly implement the research products into day-to-day activities. 
]]></description>
      <pubDate>Mon, 19 Sep 2016 16:26:24 GMT</pubDate>
      <guid>https://rip.trb.org/View/1423761</guid>
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