Principles and Guidance for Presenting Active Traffic Management Information to Drivers (2021)

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141 • Dynamic lane use control – permanent; capabilities in place, not used • Queue warning – permanent • VSL – permanent and temporary deployment ODOT has both regulatory and advisory VSL systems. The capability for lane use control is not used – pre-programmed messages may be used at a future time, e.g., red X’s. VSL systems are for weather, recurring congestion, and incidents. OR 217 was going to be congestion based, but received Federal funding to incorporate operations for weather; the software used by all the systems was written for both congestion and weather. The Mt Hood system will be mostly for weather but also congestion. ODOT has used portable trailer mounted DMS for a VSL in work zones; did it as a pilot but it is a solution that is still available. 2. For each ATM strategy, please specify how is ATM information disseminated to drivers, i.e., overhead signs (one sign for each lane), overhead signs (one sign for multiple lanes), lateral roadside signs, in-vehicle displays, smartphone applications, other. • In Portland, there are separate signs over each lane for the advisory VSLs. • The regulatory VSL is on a two-lane roadway and is on the side of the road. • The Mt. Hood VSL is on a cantilever over the shoulder even though it is two-lane roadway, due to snow blowers that could block it from view. • Eastern Oregon system has overhead signage: one sign over two lanes. 3. For each ATM strategy, what kind of signage is used? i.e., fully dynamic sign, static sign with dynamic elements, other. • Fully dynamic signs are on I-84, OR 217, Mt Hood, and at locations under construction on US 26 from I-405 to OR 217 and I-84 from I-5 to I-205. • First deployments on I-5/I-405 in downtown and at Staley’s Junction used a static sign with a changeable number. 4. What factors were used to prioritize funding for your ATM deployments? i.e., safety benefits, mobility benefits, other. • Safety is the first priority – reduced crashes. • Variability in travel time is important – trying to reduce travel time is hard to do. • After the initial deployment on SR 217, were able to use the findings on crash reduction to get TIGER grant funding for other deployments on US 26 and I-84 and safety funding on I-5 based on the reduction in crashes. 5. What resources did your agency use (e.g., documents, guidance, peer deployments) to inform the design of your ATM deployment, including signage, display format of information, content, timing, and priority for displaying information, as applicable? Staley’s Junction was first – a weekend problem with people driving to coast and a new state park. It was a problematic T-intersection and an interchange was to be built but deferred; VSL was a temporary solution there. ODOT releases grant money to do innovative projects – got money for I-5/405 for static VSL on freeway.

142 No specific documents, but did look at peer deployments. Looked at Seattle and lessons learned from other states. When OR 217 had an opportunity to do a VSL system, we looked at what other states were doing – brought in other states for a peer review, had focus groups with random drivers to see what they could understand and how to explain what they meant. Whether you do advisory or regulatory – we learned it is easier to go from advisory to regulatory than to step back. Seattle tried hard to not overpromise and not under deliver – initially saw a big drop in crashes, but later was not as good as initial – it’s important to manage expectations that these systems won’t solve everything or fix congestion. I-5/I-405 was designed to be regulatory, but it was never turned on as such; it was re-configured as advisory. Regulatory/advisory – allay fears that it’s a speed trap. How do you market it so people understand? Gauge public acceptance of system. A lot of people think it’s a great idea because of all the other drivers out there (i.e., I’m ok, but others need it). ODOT developed a video and website to help people understand the systems, did a media campaign and news stations did stories, and explained the systems, potential benefit, and help drivers know what they needed to do. Another lesson we learned: in Seattle, they display a minimum speed to show on their system. ODOT will not show a minimum speed – if it drops below 30 display “slow” instead of a speed to reduce driver confusion about a displayed speed that is higher than they can travel. We talked to law enforcement: Oregon’s basic rules say drivers can be cited for unsafe conditions – this is technically easier than issuing a citation for exceeding the speed limit because the officer does not need to know the sign display. On OR 217, we saw that people did not all go the speed advised, but since crashes dropped, you realize they do pay attention. 6. How did your agency choose the types and distribution of signs (e.g., fully dynamic over every lane at ¼-mile spacing) for your deployment? No fixed distance between signs, but looked at: where we could fit them in, the back of the queue for congestion points, and installed signs in front of those points for queue warning. We found where there would be good spacing between existing signs and these new signs AND where we could best make use of existing structures – new structures are the biggest cost, so use overpasses as much as possible to minimize costs. Spacing is a problem on OR 217 where it’s a short section with many interchanges. Chose fully dynamic signs so they could replicate any static sign – to do either regulatory or advisory, but also other options – we built in additional stock message sets to the software for future lane use control applications, if desired. 7. Has your agency made any changes to the way information is presented to drivers since your ATM deployment first began operations? (e.g., different message wording, different symbols, different spacing or sign configurations, different types of signage, distance presented upstream, different thresholds in algorithms for operations, etc.) If yes, please explain. • I-5/I-405 regulatory signage was changed to advisory before it was activated.

143 • The software included parameters that could be adjusted; some changes have been made to allow for more parameters that can be adjusted, but no major changes to the system – the same software is used for all deployments. • On I-84, used lasers to look at the pavement condition to develop a grip factor for friction between tire and pavement and slow speed limits. With two lanes in each direction, there is different usage in different lanes. For instance, if it is really snowing, most people are in right lane. The laser might see bare pavement in ruts of right lane, but not the left lane – this is a challenge for what speed to display – should we have a laser sensor in each lane? 8. How does your agency balance the needs of drivers versus the infrastructure, operations, and maintenance costs for ATM? The biggest driver is a reduction of crashes – this is the ultimate need of the driver! These systems aren’t cheap, but they are cheaper than building new lanes on the freeway. Infrastructure is already in place for communications and operations, so it’s a relatively small cost, comparatively. We cannot eliminate congestion, but we can impact the crashes. 9. Has your agency evaluated the return on investment of your ATM deployments? If so, how was this done? Yes – using crash data. We will receive funding in the next STIP to deploy VSLs on a section of I-5 from downtown to the Washington state line using safety dollars, which is based on benefit/cost analysis. Available funding is intended for smaller projects, but this ATM project was based on ROI using the dollar value of the reduction in crashes – it makes a good ROI. Did have some reduction in travel time and increased throughput during peak hour on OR 217, but didn’t go through an extensive study to see the value. Saw a 21% reduction after first 6 months of crash data; and it was still a 20% reduction after a full year. Never hinted about possible improvements in travel time when initially deployed, but did occur. 10. If you could do the ATM deployment again, what would you do differently and why? Specifically, would you use the same method for displaying information to drivers (e.g., the types and distribution of signs: fully dynamic over every lane at ¼-mile spacing)? What we’ve done has worked and is working well. There is nothing for the Portland-area deployments that would do differently. For the I-84 deployment, might put lasers in both lanes to measure bare pavement. 11. Has your agency surveyed or received feedback from drivers, either positive or negative, about the type of information they receive or the dissemination mechanism that is used? Please explain what drivers do and do not like about the deployment. ODOT didn’t do a survey, but we do get feedback – mostly positive now. ATM includes a lot of things in the state. When we initially put travel times on all DMS in the area, people wouldn’t believe the times that were on the sign: the time was what was calculated for that moment, and conditions could change as you drive to your destination. But now people cannot believe how accurate they are. Now ODOT has signs on arterials leading up to the freeway, which includes the travel time to the freeway and ramp meter time. When one of those signs was down for a week for repair, we received calls from people asking when that sign would be back up because they use that info for making decisions.

144 12. What types of information and dissemination mechanism do you believe is most effective for ATM? Full-color LED dynamic signs light up and get people’s attention versus a static sign with dynamic elements: those signs do command attention. These deployments are based on safety; given an advisory speed, the driver might not see the congestion ahead, but ODOT steps the suggested speed down slowly because you don’t want a big drop. The fact that the driver sees the message is different than normal (i.e., blank is default), lets them know to be alert and more prepared as they continue down the road – this results in reduced crashes. 13. Has your agency given any consideration to in-vehicle or smartphone application messages for deploying ATM in a connected vehicle environment? Has your agency considered phasing out the deployment or operations of traditional ITS or on-road signing, such as DMS? If yes, please explain. ODOT is anticipating for cars to provide data to ODOT systems, and to give information to drivers in the vehicle somehow. It takes time to get that deployed to every vehicle, so ODOT wouldn’t stop doing traditional deployments in the near future, but is instead planning for integration with it. ODOT is actively looking for ways to make that integration easier – follow the standard to providing information, but not looking to be the disseminator of that information in the vehicle: the equipment in the vehicle is not ODOT’s job. ODOT would provide the information in a standard format, and others would take it and provide it. ODOT is still installing new DMS and other traditional ITS. Utah respondent – Joshua Van Jura, jvanjura@utah.gov 1. What ATM strategies are currently deployed or being considered for deployment in your jurisdiction? VSLs – temporary deployments in work zones. • Background: there are a lot of 80 mph speed limits in Utah, I-215 around Salt Lake City is 70 mph. The flat, straight roadways can make 80 mph seem slow. • Objective: get a significant reduction in speed in an active work zone, predominantly for worker safety. We relate it to the concept of a school zone – a lot of people really slow down to 20 mph when the speed zone is active and people see kids. That said, you don’t comply with a flashing sign in June if you don’t see kids, and the same is true with work zones. • Design: with a gut feel, chose 1.5-2-mile lengths to reduce speeds from 80 mph to 45 mph. Have done a VSL for as short as 800 yards – and saw fantastic compliance for that. Generally, just one VSL sign is active. • Speed determination: We set the speed limit based on driver input: people are going to drive at whatever speed they feel comfortable with. The posted VSL algorithm measures the average speed within that 1.5-2-mile work zone, and then posts a VSL that is 10 mph under that average speed. The algorithm starts to stabilize, and has exclusions for low volumes. If the average speed is under 35 mph, it is defined as a queuing condition and the VSL defaults to a minimum speed. Low and high-speed thresholds are set; for high end: never post a speed above the posted speed, but more often never post above 10 below posted speed (70 mph) when workers are present; for low end: minimum speed is also set

145 (45 mph). Don’t change VSL display more often than 15 minutes; this is what the permanent, weather-based VSLs use. • May use static signs if there’s a double drop – 80 to 70 first, don’t drop the speed limit by more than 25 in a single drop. • Equipment: Initially purchased 4 VSL trailers for SMRT work zones, a contractor procured another seven for a separate project and left to UDOT, then got federal aid grant to rent seven more trailers for 2 years (cannot retain equipment with the federal grant). • Operations: generally, have static signage about the work zone, then a VSL at the beginning of the active work area, and a second VSL at end, and leap frog the first sign downstream to move with the active work zone. The signs know what order they are in based on lat/long coordinates, and both are always tied to a portable DMS that is upstream to know what direction they are facing. Some trailers have a feature to make the brake lights on the trailer blink when the radar detects vehicles that are driving 10 mph over the speed limit, but this feature is prohibited by the MUTCD. Have permanent weather VSLs also. Also use radar feedback signs – “Your speed is…” – we have never done studies to see they work, but observational data indicates that people become accustomed to them after about a week, e.g. urban arterial projects with commuters – so we move it to a different location within the project – it is a cheap technology to deploy for a potential benefit. Same for campaigns like “slow down, my daddy works here”: don’t have anything to show they actually work, but it cannot hurt. 2. For each ATM strategy, please specify how is ATM information disseminated to drivers, i.e., overhead signs (one sign for each lane), overhead signs (one sign for multiple lanes), lateral roadside signs, in-vehicle displays, smartphone applications, other. Lateral roadside sign on right side of road, for both permanent and work zones, which are on trailers 3. For each ATM strategy, what kind of signage is used? i.e., fully dynamic sign, static sign with dynamic elements, other. Static signs with dynamic numbers – for permanent and temporary deployments 4. What factors were used to prioritize funding for your ATM deployments? i.e., safety benefits, mobility benefits, other. Safety – particularly worker safety. These VSLs are a “huge win for minimal money.” 5. What resources did your agency use (e.g., documents, guidance, peer deployments) to inform the design of your ATM deployment, including signage, display format of information, content, timing, and priority for displaying information, as applicable? We reached out to variety of Utah stakeholders in interviews when developing the Concept of Operations – traffic engineers, construction personnel, and construction companies – tried to weight the wants and needs