Guide for Identifying, Classifying, Evaluating, and Mitigating Truck Freight Bottlenecks (2017)

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71 C h a p t e r 7 The bottleneck identification and mitigation process involves sorting truck bottleneck causes and matching them to mitigation strategies. Typically, state and local jurisdictions focus on truck bottlenecks on the National Highway Freight Network, the State Highway Freight Network, and local (e.g., MPO, county, city) road networks. Mitigation for bottle- necks can be either operational changes, infrastructure improvements, or a combination of both. Appropriate mitigation approaches correspond to the boxes in the flow chart in Figure 7-1. This chapter describes options for mitigating a wide range of truck bottlenecks. It is structured with the following sections: • Section 7.1. Matching Mitigation Options to Bottleneck Causes, • Section 7.2. Mitigation Options for Recurring Congestion, • Section 7.3. Mitigation Options for Nonrecurring Congestion, • Section 7.4. Mitigation Options for Operational Deficiencies, • Section 7.5. Mitigation Options for Geometric Deficiencies, • Section 7.6. Mitigation Options for Special Event Bottlenecks, and • Section 7.7. Examples of Truck Bottleneck Mitigation Efforts. 7.1 Matching Mitigation Options to Bottleneck Causes There are a large number of potential approaches to mitigating the identified truck bottlenecks. A selected approach should consider the following: • The causes of the delays, • The geographic and geometric attributes of that location, • The operational characteristics of the roadway, • The organization of the agencies working on that facility and other facilities that influence the operation of that roadway, • The operational systems currently implemented on the road (or in the larger region that have been demonstrated effective and/or have public support), and • The type of funding available. There is no simple, automated process that can determine the “best” mitigation strategy for any given bottleneck. The selection of the appropriate strategy requires knowledge of all of the above factors. For example, an analysis that focuses on mitigating air quality impacts of bottlenecks will seek strategies that reduce truck VMT in addition to reducing truck idling. This can include Options for Mitigating Truck Bottlenecks

72 Guide for Identifying, Classifying, evaluating, and Mitigating truck Freight Bottlenecks providing incentives to have more trucks operate during nighttime periods where congestion is minimal. Truck emissions factors will need to be applied to various mitigation strategies to determine which one(s) are the most effective. Typically, mitigation for truck bottlenecks can be divided into a number of categories on the basis of the basic causes/attributes of delay. These include the following: • Recurring congestion (too much traffic volume), • Nonrecurring congestion or delays, • Geometric deficiencies, • Operational deficiencies, and • Event congestion. Each of these causes of delay requires different types of mitigation, and the design and implementation of those mitigation efforts depends on the organization and operational relationships of the various trans- portation agencies and political jurisdictions that operate the road or that provide services in that geographic region. The subsections below briefly describe each of these categories of bottlenecks and illustrate typical mitigation strategies that agencies frequently consider to mitigate the resulting freight delays. Table 7-1 summarizes the mitigation options to consider for each truck bottleneck type. It should be noted that the selection of mitigation options should be done in cooperation with both public-sector and private-sector freight stakeholders. It is particularly important to be proactive with the private-sector community (including shippers) to ensure that the mitigation option will likely have the intended impact on the bottleneck. The remainder of this chapter discusses mitigation options in greater detail. Case Study Highlight A number of freight mobility efforts have been performed in the state of Florida by the Florida DOT and its partnering agencies. One example is the Tampa Bay Regional Strategic Freight Plan: An Investment Strategy for Freight Mobility and Economic Prosperity. The plan steps the reader through the regional modal assets and identifies a number of freight mobility needs (capacity, operations, maintenance, safety/security). A process is presented for scoring the needs; the freight corridor-based project needs are illustrated in maps by county in the region. The document concludes with specific implementation guidance for recommended freight-related improvements. More details are in Appendix B. Bottleneck 1. Mitigation: Capacity Expansion, Programmatic Travel Demand Management Efforts 2. Mitigation Geometrics Changes 3. Mitigation Operational Changes For all Vehicles For Trucks Only Too Many Vehicles Roadway Limitations Operational Limitations Roadway Limitations Operational Limitations 4. Mitigation: Truck- Oriented Operational Changes 5. Mitigation Truck- Oriented Geometric Changes Figure 7-1. Mitigation approaches for all vehicles and trucks only.

Options for Mitigating truck Bottlenecks 73 Cause Of Bottleneck Mitigation Measure Options to Consider Recurring Congestion Add capacity Reversible/convertible two-way left-turn lanes ITS solutions: ramp metering, real-time traveler info (e.g., sharing peak demand data), appointment systems, load-matching, etc. Travel demand management (TDM) solutions: truck tolling, off-peak-hour delivery options, etc. Truck mode shift to rail, water, or air modes Variable speed limits during shoulder periods of recurring congestion Managed travel lanes to allow for shoulder running Automated platooning of trucks and/or autos Traffic Incidents Real-time traveler info via mobile devices and CMS Advanced closure notifications Queue detection and warnings before known bottlenecks, especially where site distance is limited Install CCTV at high-incident locations to allow for faster response time Traffic control, such as alternative routing information and alternative timing plans for signalized intersections Crash investigation sites and refuge areas Gate/border crossing technology improvements, such as appointment systems, RFID readers, congestion-based toll. Preregistered toll options, etc. Truck tipping warning signs Work Zones Advanced closure notification Coordinated traffic control and real-time traveler information Weather DOT coordination with NOAA to provide real-time traveler information Ice detection, warnings, and anti-icing on bridges and roads Winter maintenance programs (snowplowing, avalanche control, and deicing) Runaway truck ramps Table 7-1. Summary of mitigation options to consider for each truck bottleneck cause. (continued on next page)

74 Guide for Identifying, Classifying, evaluating, and Mitigating truck Freight Bottlenecks Cause Of Bottleneck Mitigation Measure Options to Consider Poor Signal Timing Signal synchronization Signal prioritization for trucks Right-/left-turn lane additions Appropriate truck turning radii Improve site distance (remove obstructions, improve lighting, etc.) Improve geometry at signalized intersections, including continuous flow intersections, diverging diamond interchange, etc. Nonrecurring—Special Event Traffic Outreach and coordination with trucking industry Signage where appropriate Real-time traveler information Managed travel lanes to allow for shoulder running Adaptive traffic control Peak-hour signal timing Geometric—Up And Down Grades, Super- Elevations Truck climbing lane Truck deceleration lane Runaway truck ramp Leveling or changing slopes Tunnels Geometric—Horizontal Reconstruct to standard Curves Increase signage and lighting Queue detection and driver warnings Truck bypass Geometric—Lane Drops Extend length of lane Construct auxiliary or passing lane Geometric – Short On- or Off-Ramps Extend length of ramp Add deceleration or acceleration lane Construct auxiliary lane Consider use of shoulder to extend ramp Table 7-1. (Continued).

Options for Mitigating truck Bottlenecks 75 Cause Of Bottleneck Mitigation Measure Options to Consider Geometric— Merge/Diverge Congestion Add auxiliary lane Interchange consolidation via collector-distributor system Restriping merge/diverge areas to provide additional lanes Ramp metering Syncing arterial signals to moderate flow of traffic merging onto and exiting the mainline Separate truck/auto traffic Geometric—Narrow Bridges Widen travel lanes on bridges Widen shoulders on bridges Geometric—Tunnels Reconstruct to add necessary height and/or adequate travel lane widths and shoulder widths Geometric—Narrow Travel Lanes Restripe to widen travel lanes Consider use of shoulder or widening Process Delays— Gate/Weigh Station Gate/border crossing technology improvements, appointment systems, radio frequency identification (RFID) readers, congestion-based tolls Processing (CBT) preregistered toll options, etc. Weigh stations: consider weigh-in-motion devices to improve enforcement, reduce processing delays, and prevent queue spillover onto mainline travel lanes Increased gate or booth staffing Process Delays— Parking Shortage And Access Management Increase number of truck parking spaces Utilize “smart parking strategies” that provide information on location and timing of available truck parking spaces Allow for reservations to be made for truck parking spaces Optimize driveway location and design for truck access Design frontage roads for freight facility access Table 7-1. (Continued). (continued on next page)

76 Guide for Identifying, Classifying, evaluating, and Mitigating truck Freight Bottlenecks Cause Of Bottleneck Mitigation Measure Options to Consider Process Delays—Permit Acquisition Increase processing time for permit acquisition Allow for broader application of current permit categories Reduce number of trip types for which a permit is required Automate permit acquisition process Process Delays (Other)—Truck Prohibitions/Route Restrictions: Size/ Weight, Hazardous Materials, And Oversized Loads Investigate reason for prohibitions/restrictions Match truck routes with appropriate infrastructure considering height and weight limits Table 7-1. (Continued). 7.2 Mitigation Options for Recurring Congestion Recurring congestion is congestion that routinely occurs at the same locations and same time periods. It is caused when more traffic (and truck) demand is present than the road can serve. The following four basic approaches to mitigating recurring congestion are: 1. Capacity expansion, 2. Operational improvements, 3. TDM, and 4. Provision of alternative capacity. Capacity expansion is a common approach to an imbalance of travel demand and roadway capacity. Roadway agencies have historically looked to expand the number of lanes on roads that experience rou- tine congestion. This is still a reasonable approach when the cost of that expansion is modest and when continued growth in travel demand is forecast. However, in many parts of the country road expansion is prohibitively expensive or politically unfeasible. As a result, other approaches to capacity expansion also are commonly explored. One such approach consists of operational improvements. For exam- ple, retiming traffic signals can lead to a considerable increase in vehicle throughput on arterials. For arterials that serve large truck movements, retiming signals to meet the acceleration profiles of the trucks using that arterial can result in better traffic progression on the arterial and conse- quently increased vehicle throughput and decreased congestion and delay. A variety of other operational and geometric improvements are appli- cable to different location-specific conditions. Common operational improvements on freeways that agencies frequently implement include: • Ramp meters, • Variable speed limits, Capacity expansion is a common approach to an imbalance of travel demand and roadway capacity. . . . retiming traffic signals can lead to a considerable increase in vehicle throughput on arterials.

Options for Mitigating truck Bottlenecks 77 • Active traffic management, and • Lane restriping. On arterials, operational improvements designed to increase throughput can include: • Signal retiming; • Improved channelization; and • Adding or changing traffic controls (e.g., replacing a signal with a roundabout, or removing stop signs that do not meet warrants). The third approach to decreasing a recurring bottleneck is TDM. TDM involves modifying the options, incentives, and disincentives that shippers and travelers have with regard to travel through the bottleneck. The intent is to shift demand from the periods that are congested to modes, routes, or times of the day where or when additional capacity is available. For example, carpool incentives that cause drivers of single- occupancy cars to share rides with other people using that roadway reduces vehicle demand in the corridor without changing actual person throughput. The reduction in vehicle demand causes reductions in con- gestion for all vehicles, including trucks. Similarly, shifting traffic to noncongested periods allows the shifted traffic to travel during less congested periods, while lowering congestion during the congested periods. Time-of- day shifts may be achieved through a variety of informational and incentive-based programs and can be applied to both truck and car travel. For example, some urban areas (e.g., New York) have instituted nighttime freight delivery programs in which incentives encourage freight deliv- ery services to move to evening hours. (27) These programs target both the trucking industry and the companies receiving the freight shipments. The New York program showed how late- night deliveries saved all parties time and money for their goods delivery by decreasing the time required to travel from the distribution center to the destinations, decreasing the distance between truck parking and the goods’ ultimate destination (i.e., decreasing the time required to move the goods from the truck to the store and for the store to handle the delivery). Conse- quently, trucks moved from congested periods to uncongested periods, resulting in lower congestion levels for all concerned and decreased cost for the freight deliveries. TDM programs can be almost infinitely creative. They can involve both incentive programs, to encourage travel behavior that low- ers travel during congestion time periods and on congested facilities, and dis incentive programs, designed to discourage travel behavior during those periods and on specific facilities. They can be targeted at both shippers and travelers (e.g., congestion pricing on tolled facilities). They also can be targeted at the customers of the shippers (e.g., cost incentives at ports to pick up containers during off-peak hours). The final category of capacity improvements is the provision of alterna- tive capacity. This category is essentially a combination of all three of the above categories but is applied to other transportation facilities that serve as alternatives to the congested facility. A good example of this approach is integrated corridor operations. On an integrated corridor, parallel roadways are operated in a coordinated fashion. As one road begins to reach capacity, traveler information systems inform travelers of the availability of better-performing, parallel roadways that serve the same Case Study Highlight The Delaware Valley Regional Planning Commission (DVRPC) 2012 Congestion Management Process (CMP) report identified, classified, and evaluated bottlenecks in the region and provided mitigation strategies specific to each bottleneck. One particular DVRPC CMP objective is “maintain existing core transportation network,” and several of the criteria and strategies relate to freight and goods movement. DVRPC also has a PhillyFreightFinder to pinpoint freight facilities and freight activity in the region. More details are in Appendix B. TDM involves modifying the options, incentives, and disincentives that shippers and travelers have with regard to travel through the bottleneck.

78 Guide for Identifying, Classifying, evaluating, and Mitigating truck Freight Bottlenecks corridor. The operational controls on those roads are then optimized to accept increased travel demand as travelers shift their route to take advantage of the parallel facilities. This approach also includes making improvements to alternative modes so that mode shifts may more readily occur to decrease demand on the congested facility. 7.3 Mitigation Options for Nonrecurring Congestion Many bottlenecks form not because demand increases traffic volumes beyond the design capacity of the roadway, but because a disruption on that roadway causes functional capacity to fall below the actual demand. The most common disruptions are: • Vehicle crashes; • Other types of incidents (e.g., debris on the road, disabled vehicles, police activity on the side of the road); • Construction and maintenance activity (work zones); and • Bad weather. The appropriate actions that reduce the formation of bottlenecks under these circumstances include both actions designed to reduce the occurrence of these events (e.g., changes that reduce the frequency and severity of crashes) and activities meant to restore roadway capacity after one of these events (e.g., incident response activities and snow and ice control efforts). The specific activities taken are a function of the local nature of the events. For example, snow and ice control are not useful activities to consider in Los Angeles, but they certainly are in Buffalo. A desktop analysis and early field analysis performed for a road segment in Buffalo might show that a large portion of delay occurs in the winter when snow has fallen. That knowledge should lead to a review of the snow plow, snow removal, and winter weather traveler informa- tion systems in use. Such a review would entail not only the activities taking place, but also the interactions among various agencies that work to mitigate winter snow conditions. Information on handling winter snow activities would be obtained from national resources such as the U.S.DOT Clarus effort. This would then be compared to information on road weather programs in Buffalo, and, where appropriate, changes to the current program would then be implemented. It is only at this local level of detail that appropriate mitigation can occur. Similarly, in Los Angeles, it might be shown that vehicle crashes contribute extensively to cor- ridor delay. Just as Buffalo already has an extensive winter roadway program, the Los Angeles metropolitan area already has an extensive incident response program. But if the field analysis showed that incidents were still contributing significantly to delays, additional attention would likely be warranted on ways to both lower crash rates and reduce the delays those crashes create. Similarly, if work zones were a significant cause of bottleneck delays, the agency would examine the current work zone management practices, compare those practices with the state- of-the-art and state-of-the-practice activities, available through FHWA and other national organizations, and implement changes as appropriate for local conditions. These conditions would include the available budget, the roadways where work zones were operating—which, in turn, would affect the appropriate work zone management activities that could/should be implemented—and the local agency responsibilities and interactions to be accounted for in the design of a work zone management plan. The field analysis would examine both current local incident response efforts and the national guidance available through FHWA, the Strategic Highway Research Program 2 (SHRP 2), and other national bodies.

Options for Mitigating truck Bottlenecks 79 7.4 Mitigation Options for Operational Deficiencies Operational deficiencies occur when the existing operational con- trol system is not working as well as it could be or when substandard roadway geometrics or a lack of adequate loading and unloading facilities force trucks to slow. This results in reduced roadway capacity, and there- fore, many of these situations also are identified as recurring congestion, as noted above. The classic definition of an “operational deficiency” is when the signal system on an arterial is not well timed. In such a case, the roadway serves fewer vehicles than it could, and those vehicles experi- ence far more delay than they should. When this occurs, simply retiming the signals on the arterial can significantly decrease vehicle delay at rela- tively modest cost. Operational improvements oriented toward cars might also improve truck mobility. If the roadway in question is a high-volume truck route this might increase the priority for roadway infrastructure funding to address the bottleneck but typically the operational improvements will not be specifically truck-oriented. Some operational mitigation approaches specifically address trucks. These approaches may be relevant on freight routes. One approach is to adjust supply and demand through pricing. (28) Congestion or peak-period pricing uses fees or tolls for road use, which can vary by vehicle size. This can change the truck travel patterns and demand on a roadway. The congestion pricing toll “rings” as found around a number of European cities with different pricing for trucks are an example of this approach. Another operational approach is to provide trucks alternatives as to how, when, where, and if to travel. The objective of this approach is to reduce the number of vehicles on a given road dur- ing congested times. For trucks this can include off-hour deliveries and expanded terminal hours such as for seaports as well time-of-day truck travel and size restrictions. A related approach is Active Traffic management (ATM), which can open and close lanes and allow trucks at certain times or in certain lanes. (29) Time-of-day noise restriction and modifying oversize and over- weight rules for truck can also change their operational travel patterns. Technology-based operational solutions can also reduce operational bottlenecks. Examples of such applications for trucks include retiming of traffic signals in high-activity freight areas so they better match the acceleration patterns of trucks, and freight-oriented traveler information, such as the U.S.DOT’s Freight Advanced Traveler Information System (FRATIS), (30) that helps truckers to avoid areas and times of congestion. A good field analysis can often identify other operating improve- ments that, if implemented, should result in significant improve- ments in overall operations. These may include minor geometric changes (restriping), the addition of a load zone, changes in operat- ing controls (e.g., when reversible roadways change directions, or the methods used to close, safety check, and then reopen those road- ways in the opposite direction), and adoption of new policies that improve operations (e.g., limiting construction activities to times of lower traffic volume). Fixing operational deficiencies also can include modest geometric improvements. An example is the addition of truck climbing lanes in hilly regions. Such a change does not increase the speed of heavily loaded trucks, but it does provide lightly loaded trucks the ability to Case Study Highlight A study performed for the Texas DOT documented how safety and operations are improved with low-cost freeway bottleneck removal projects. The study recommends collecting five types of data, including volume counts, travel times, videotape, drive-through video, and origin-destination data. Researchers emphasize the importance of conducting the analysis both before and after a project is implemented. The benefit-to-cost ratios of the projects ranged from 400:1 to 3:1 for the four projects evaluated, and all the sites experienced reduced incident rates. More details are in Appendix B. Operational deficiencies occur when the existing operational control system is not working as well as it could be or when substandard roadway geometrics or a lack of adequate loading and unloading facilities force trucks to slow.

80 Guide for Identifying, Classifying, evaluating, and Mitigating truck Freight Bottlenecks pass slower moving vehicles. Similarly, deceleration lanes on steep downhill grades allow trucks to maintain lower speeds and control. Another common feature, runaway truck ramps, can be installed on steep downhill sections. These ramps protect against crashes that commonly occur when a truck’s brakes fail or during inclement weather, such as snow and ice, when trucks lose traction. (See Exhibit 7.1.) 7.5 Mitigation Options for Geometric Deficiencies Roadway design features (tight curves, narrow lanes, etc.) that slow travel for all vehicles can be identified by slow travel independent of roadway volumes. Mitigation is typically an update of the physical roadway infrastructure. As with the mitigation for too many vehicles, any fix ori- ented toward cars will also improve truck travel if the updated geometrics address truck dimen- sions and operating characteristics. It is important to consider a design vehicle that is a truck if the roadway is a significant freight route. Mitigating truck bottlenecks from geometric deficiencies is particularly important, because trucks have different operating characteristics from cars. Some of these differences include: • Trucks occupy more horizontal and vertical roadway space; • Trucks require more room for turns; • Trucks require more roadway to brake and stop; and • Depending on the power-to-weight ratio, trucks can have notably different acceleration and characteristics and performance on grades. Roadways that are not designed to truck characteristics can result in truck-only delays and bottle- necks. Mitigation approaches addressing this type of bottleneck need to identify a roadway’s attri- butes that reduce a truck’s speed (and reliability). Two sources can provide general information on roadway design characteristics and limitation that either cause or contribute to bottlenecks. One is the geometric roadway design manuals that address different design standards, often using truck Source: Tennessee DOT. Source: Colorado DOT. Exhibit 7.1. Truck ramps.

Options for Mitigating truck Bottlenecks 81 design vehicles [for example, a wheel base 40 truck (WB-40)] for different sizes and types of trucks. In particular, a truck’s performance limitations are linked to tight curves, hills, and some types of intersections. A commonly used source of geometric design information, with chapters on trucks, is the AASHTO “Green Book”: A Policy on Geometric Design of Highways and Streets. (31) The crash and safety literature provides a second perspective into roadway attributes that contribute to reduced truck performance. Attributes tied to more frequent truck safety con- cerns can be at locations which, in the worst case, cause a crash that slows or closes a road. More commonly, the same locations are also places that are more difficult for truck operations, requiring prudent drivers to slow and drive more carefully. In many cases, these are locations that are not problems for cars and a truck-specific bottleneck analysis is required to find infra- structure problems. For example, locations with inadequate vertical curves can contribute to truck rollovers but may not be problems for cars simply because trucks (such as tractor-trailer combinations) are vulnerable due to their height and high center of gravity. (32) Based on the safety and roadway design literature (more information is in Appendix E), road- way attributes that can slow trucks as well as example infrastructure mitigation approaches to improve those locations (example are also found in Table 8-1) include the following: • Tight turns can cause truck drivers to slow or maneuver to avoid having the truck’s wheels track off the roadway or even off the pavement. An infrastructure fix is to increase the turn’s radius which can be as simple as adding more pavement, or difficult if it requires major con- struction or demolition of existing structures. • A vertical curve is where there is an intersection between two slopes on a roadway (i.e., roll- ing roads are an example). Typically trucks have to travel vertical curves more slowly than cars because of their weight-to-power ratio and their acceleration and braking characteristics. Another aspect of vertical curves that can cause truck delays is sight distance which, at night, also impacts the effective distance for a truck’s headlights. Vertical curves can be modified to change a road’s profile and grade. This tends to be costly but this cost does vary depending on maximum and minimum gradients, required sight distance criteria; surrounding land and topography; and other roadway features such as horizontal curves. • A horizontal curve is a primary truck safety and design consideration. Truck travel that is too fast for a horizontal curve can cause trucks to skid off of the road or overturn. (33) The American Transportation Research Insititute (ATRI), for example, mapped roadway nationally that had a high frequency of large truck rollovers. (34) Notable horizontal curve problems for trucks are freeway on- and off-ramps. (35) There are number of possible mitigations for horizontal curve limitations, including warnings, enhancing delineation along the curve, pro- viding adequate sight distance, widening the roadway, improved or restored super elevation (the road’s cross section), or just modifying the horizontal alignment. • In general, narrow lanes can reduce a trucks driver’s margin of error in operating larger vehicles. Mitigation can include lane widening if there is right-of-way available or adding median barriers. • Tunnels and bridges often have limitations similar to narrow lanes. Mitigation can include reconstruction to add height or width. • The number of lanes, particularly on single lane roads, can delay trucks, because truck have difficulty passing slower vehicles, which causes queues to form. Lane drops are difficult loca- tions for trucks because their slow acceleration rates and length make it more difficult to merge into traffic. Mitigation can include adding a lane, extend lanes to remove lane drops, or adding passing lanes on single lane roads. • Narrow shoulders can slow truck travel because there is limited area to maneuver to avoid crashes and they also reduce the ability of a truck to turn at intersections. Mitigation can include shoulder widening if there is right-of-way available. • Both up and down grades can reduce truck’s speed. Because of a truck’s power-to-weight limitation many trucks are slow going uphill. Truck drivers also brake going downhill to avoid going too fast. Mitigation of bottlenecks due to grades can be costly and include leveling and

82 Guide for Identifying, Classifying, evaluating, and Mitigating truck Freight Bottlenecks changing the road slope, adding truck climbing lanes, or using tunnels to bypass the grades. Emergency runaway truck ramps also improve truck safety on steep downhill grades. • Intersections and merges can be difficult for large vehicles. Intersection design can vary considerably but, for trucks, intersections on highways with partial or no access control pre- sent significant operational and safety concerns. Signalized intersections can also create truck bottlenecks particularly if not timed for a truck’s slower acceleration patterns. Short freeway on-ramps or off-ramps can be a problem because trucks accelerate more slowly into traffic. There are many mitigation approaches for intersections. Fixes include altering signal timing, changing intersection angles and turn radius, lengthening ramps, adding turn lanes, and widening shoulders or medians. Another option is conversion to a roundabout. • Additional roadway factors may impact truck travel independent of cars but may be harder to isolate using roadway attribute data. These factors could include poor sight distances, divided as opposed to undivided highways, and multiple driveways (due to access control). Knowledge of these factors can be used to make a field visit more effective. 7.6 Mitigation Options for Special Event Bottlenecks Special event congestion is “routine” in that it occurs as a result of increased traffic volumes associated with specific events. However, the events themselves do not occur during normal weekday commute times and may only occur a limited number of times during the year. Two specific types of “event” congestion delays are recreational travel and major event travel. Recreational travel (trips to the beach or ski areas) are generally predictable by day of week and time of year. They tend to involve very heavy directional traffic volumes on one or two days of a week (to the beach on Thursday and Friday evenings, and home on Sunday afternoon and evening). Freight bottlenecks form when these large traffic movements increase the background traffic. Mitigation typically includes deployment of traffic control plans specifically intended to handle the expected recreational traffic patterns, placement of incident response teams during peak recre- ational movements, and TDM efforts aimed at shifting the recreational travel to other modes (e.g., buses to ski areas) or less congested periods (e.g., “leave by 11 a.m. if you want to avoid the Thanks- giving exodus”) based on analysis of historical travel patterns. The field analysis can provide the historical travel information needed to develop, optimize, and deploy these mitigation approaches. Major event traffic tends to be even larger and more directional relative to typical background traffic. For example, large sporting events or public festivals (e.g., Fourth of July fireworks) attract very large crowds to the stadium area or park during the hours before the event start, and then a major exodus occurs when the event concludes. Typical mitigation involves the development of spe- cial traffic management plans, specifically designed to meet the size and timing of expected traffic. These plans typically involve hiring and deploying traffic management personnel and equipment. 7.7 Examples of Truck Bottleneck Mitigation Efforts Many state DOTs have programs and budgets designed to locate, prioritize, and fix bottlenecks for all vehicles. There are a number of approaches to address roadway congestion, including capacity expansion, incident removal, and programmatic TDM. Typically, state DOTs fund travel speed-based approaches that improve travel for all vehicles and are not focused specifically on trucks. While the volume of trucks, or the importance of the road as a freight route, might change the funding priority of a bottleneck, in most cases, truck flow is improved simply because travel flow for all vehicles is improved. Two specific types of “event” congestion delays are recreational travel and major event travel.

Options for Mitigating truck Bottlenecks 83 MPO CMP plans were found to be a common place for truck bottleneck mitigation efforts due in part to their responsibility for air quality conformity, but also due to their role in retain- ing and creating jobs and promoting economic sustainability. In these instances, improving goods movement is typically a part of the larger long-range plan, and the project screening and prioritization process often considers goods movement benefits. Another observation is that CMP analyses typically focus on the most congested portions of the day (peak periods) and in many cases that is not when trucks are out on the road; therefore, some of the truck impact may not be captured in typical CMP analyses. The following documents provide good examples of how to mitigate truck bottlenecks. More information on each of these studies is provided in Appendix B. • Delaware Valley Regional Planning Commission (DVRPC) 2012 Congestion Management Process (CMP); • Application of Congestion Management Process (CMP) Strategies in Miami-Dade County; • Tampa Bay Regional Strategic Freight Plan; • Southern California Council of Governments (SCAG) Regional Transportation Plan— Congestion Management, Goods Movement, and Truck Bottleneck Strategy; • Mitigation of Recurring Congestion on Freeways; • Improving Safety and Operation with Low-Cost Freeway Bottleneck Removal Projects; and • Framework for Analysis of Recurring Freeway Bottlenecks. 7.7.1 Florida DOT Example of Mitigating Truck Bottlenecks Many transportation agencies have asset inventories in GeoData catalogs that can be extracted and analyzed using GIS software. (36, 37) Figure 7-2 is an example roadway GeoData catalog for the Florida DOT. The use of these databases with GIS software enables spatially Source: http://www.dot.state.fl.us/planning/statistics/gis/roaddata.shtm. Figure 7-2. Example GeoData catalog from the Florida DOT.

84 Guide for Identifying, Classifying, evaluating, and Mitigating truck Freight Bottlenecks linking segments identified as a bottleneck to different geometric characteristics of that road- way segment. 7.7.2 Washington State DOT Example of Mitigating Truck Bottlenecks Specific roadway attribute data can be used to indirectly or directly identify possible bottleneck causation. For example, Table 7-2 lists general infrastructure attributes that potentially impact truck operations and associated roadway geometric infrastructure attributes as found in the Washington State Department of Transportation’s (WSDOT’s) GeoData catalogs. Some roadway attributes such as steep grades can be readily assigned as a source of truck delay. Other causes, such as intersection type, may only be suggested by the GIS process and will require a field check and local knowledge to develop bottleneck causation. This case study is an example of a desktop exploration of a truck bottleneck using a GIS software desktop and WSDOT’s GeoData catalog (Figure 7-3). Ideally, this process will be followed up with local knowledge and a field check. The Figure 7-3 bottleneck location is a rural section of Interstate 90 in Washington State (roughly mileposts 79.0 to 80.5). The roadway is a divided highway and is two lanes each way with a posted speed limit for trucks of 60 mph. Probe GPS data from WSDOT’s Freight Performance Measurement Program (38) indicates that, for westbound travel, an average truck travel speed is 48 mph with 38 percent of trucks traveling below 60 percent of posted speed limit. WSDOT considers this roadway segment a freight corridor of the highest importance with an average volume of 6,000 trucks per day [State Freight and Goods Transportation System (FGTS) truck tonnage classification of T-1 with more than 10 million gross ton per year]. A GIS-based exploration of the attributes of this roadway section suggests a number of road- way attributes that might slow trucks and create this bottleneck: • The GeoData catalog indicates the roadway is a divided highway with standard lanes and shoulder widths and without any special lanes (such as a truck climbing lane). The legal speed limit for this roadway section for trucks (60 mph) can also be found in the catalog. • In WSDOT’s data catalog, the terrain for this roadway section is noted as rolling. Extraction of vertical alignment data shows a 3.75 percent grade around milepost 77.0. The typical maxi- mum allowable grade on Interstates is 6 percent. • The horizontal alignment data indicate the roadway has a tight curve also around milepost 77.0 (on the grade). • The DOT’s mapping functions and intersection inventory indicate an intersection at milepost 77.2, which has an on-ramp resulting in merging traffic. This ramps merges from a weigh sta- tion that indicates, when the station is open, many trucks are trying to merge into traffic. An on-ramp just upstream serves all traffic (milepost 77.8). • At the top of the curve, the GeoData catalog identifies a 250-foot-long bridge over a river (milepost 76.05). Considerable extra information is available from WSDOT as to the bridge’s height and width and for any bridge-related truck restrictions. This GIS analysis indicates a variety of roadway attributes that can slow trucks include a merg- ing from a weigh station, a merge with all traffic, a curve on a grade, and a bridge. This is an example of how detailed roadway attributes can support an analysis of roadway characteristics and can assist in analyzing bottlenecks. This type of analysis is better supported by specific short roadway segments (on the order of 1 mile or so in length), which allows a focus on and identification of specific roadway attributes. Longer segments (such as found for many of the TMC segments in rural area as used by NPMRDS) are less usable when analyzing specific roadway geometrics.

Options for Mitigating truck Bottlenecks 85 Bottleneck Characteristic Roadway Feature Measured Supporting Variables Available in WSDOT’s GeoData Catalog Truck swept path width (turn area) Tight curves at intersections cause trucks to track off the roadway Horizontal alignment Intersection information Vertical curves Alignment of rolling roads with sight distance and headlight distance limitations Roadway Vertical Alignment Design Speed Vertical Curves Horizontal curves Radius of tight curves that can contribute to running off the road or rollovers and a need for trucks to slow down Roadway Horizontal Alignment Design Speed Horizontal Curve Where Design Speed Is Greater Than or Equal to 20 Roadway Design Speed Horizontal Curve Where Design Speed Is Less Than 20 Lane width Roads with narrow lanes slow trucks Lane Width Roadway Special Use Lanes (Truck Climbing Lanes, Acceleration Lanes) Medians Number of lanes Two-way, two-lane roads and lane drops can be slower for trucks and passing slow vehicles is a challenge Number Of Lanes Roadway Special Use Lanes (Truck Climbing Lanes, Acceleration Lanes) Medians Shoulder width Width of shoulder—narrow shoulders contribute to slow truck travel Shoulders Width (Inside And Outside) Grades Uphill grades slow a truck because of truck power-to-weight limitation Downhill grades require trucks to brake to avoid excess speeds Terrain Type Vertical Curves Special Use Lanes (Climbing Lanes) Grades (Calculated Using Readily Available Outside Data) Table 7-2. Bottleneck characteristic and supporting data in WSDOT’s GeoData catalog. (continued on next page)

86 Guide for Identifying, Classifying, evaluating, and Mitigating truck Freight Bottlenecks Bottleneck Characteristic Roadway Feature Measured Supporting Variables Available in WSDOT’s GeoData Catalog Other Information Truck relevant route and other travel factors that might support a field analysis Freight and Goods Transportation Systems Routes (Truck Relevant Routes) Truck AADT Divided Highways Urban-Rural Bridges Mileposts Intersections and ramps (curb return radii at intersection and ramps) Certain intersections can be difficult for trucks due to tight turning radii, poor sight distance and signal timing that does not match a truck’s acceleration rates Intersections Type (Signalized Or Nonsignalized and Other Information) Ramps Turn Lanes Functional Class Table 7-2. (Continued). Figure 7-3. Bottleneck location with example roadway GIS attribute data – intersections, grade, and mileposts.