12th International HOV Systems Conference: Improving Mobility and Accessibility with Managed Lanes, Pricing, and BRT
BREAKOUT SESSION — MONITORING, EVALUATING, AND REPORTING FOR MULTIPLE USER GROUPS
Neil Spiller, Federal Highway Administration, Presiding
Using Real-Time Data to Evaluate HOV and General-Purpose Lanes
Robert Benz, Texas Transportation Institute
Robert Benz discussed the use of real-time data to evaluate the HOV and general-purpose freeway lanes in Houston. He described the measures of effectiveness, data sources, and analysis techniques used in Houston. He also summarized the methods used to disseminate information and future activities.
- A number of measures of effectiveness (MOEs) can be used with HOV facilities. Potential MOEs address safety, vehicular volume, LOS, travel time and speed, and trip-time reliability. Other possible MOEs include modal shift, person movement, and environmental factors.
- A number of data sources are used in monitoring the Houston HOV lanes. Travel time and speed data are obtained through the AVI system. Incident and safety information is obtained from the Regional Incident Management System (RIMS). Historical data on vehicle volumes and vehicle occupancy is available and counts continue to be taken on a quarterly basis. Automated counts are also available from tubes, loops, and the Regional Transportation Management System (RTMS).
- The AVI system covers some 70 percent of area freeways. There are over 250 readers spaced every one-to-five miles. There are over one million tags in the area. Approximately 1.5 million tags are read per day. Approximately 72 percent of the general-purpose lanes and 36 percent of HOV lanes are covered by the AVI system.
- The AVI system includes the transponder tags in vehicles and the AVI reader stations. The stations include multiple antennas to cover all the travel lanes. Tags are read in a single direction.
- The process for data acquisition and data processing of travel times using the AVI system involves a number of steps. When a vehicle with a tag passes under an antenna the tag identification is read. The tag identification, location identification, and time stamp are transferred by modem to a central processor that contains the AVI tag database.
- The tag identification, the location, and the timestamp for each read are matched in the data processing system. The tags are matched, an error screening is conducted, and average travel times and speeds are calculated. The output includes a real-time dataset and a historical post-processed dataset.
- The RIMS monitors the motorists assistance program (MAP), traffic incidents, and major incidents, such as plant explosions and sporting events. Information collected includes the detection time, the time the incident was verified, the time it was cleared, and the number of lanes blocked.
- Historical data on the Houston HOV lanes includes manual vehicle occupancy counts, violation rates, and onboard bus surveys. Automated volume and classification counts are also included in the historical data.
- A quality assessment/quality control (QAQC) process is conducted on the AVI data. Travel times and volumes on the HOV lanes and general-purpose lanes are calculated, as are built-up travel times. The travel time difference for the HOV lanes and the general-purpose lanes is calculated and compared. A variety of summary tables and reports are generated.
- The data aggregation methodologies include a snapshot, which aggregates multiple segments with the same start time, and built-up, which aggregates multiple segments. The analysis process includes calculating differences between the general-purpose lanes and the HOV lanes. The savings by volume and occupancy can be expanded and road user costs computed. A variety of graphs, tables, and reports are prepared. Operational reports can be presented with daily, weekly, monthly, quarterly, and yearly data.
- A variety of methods are used to disseminate real-time information on the status of the HOV and general-purpose lanes. These methods include the real-time traffic map on the Internet, DMS, local radio, and portable devices. Mobile data dissemination applications include traffic alerts, which can be provided to individuals through cell phones, PDAs, and desktop computers.
- A number of enhancements to the AVI system are planned. These enhancements include expanding the AVI system to the entire freeway system, automating additional processes, and assessing dynamic routes versus line-haul routes. The ability to predict travel times based on incidents is also under study. Expanding the use of information for operational assessments and the potential use in value pricing are also being explored. Using the system for operating assessments, including examining clearance, enforcement, and geometrics is being considered.
Monitoring and Reporting on HOV Lanes in the Puget Sound Region
Mark Hallenbeck, Washington State Transportation Center
Mark Hallenbeck described the HOV lane performance monitoring program in the Puget Sound Region. He discussed the performance elements included in the monitoring program, the automated and manual data-collection techniques, and the data-analysis methods. He also provided examples of different methods and techniques for reporting the results of the monitoring program.
- The HOV lane monitoring program focuses on four major elements. These four elements are vehicle volumes in the HOV and general-purpose lanes, vehicle-occupancy levels, bus ridership, and travel times in the HOV and general-purpose lanes.
- The WSDOT freeway management system provided automated data collection for some of these performance indicators. Loop detectors used for controlling the ramp metering system provide data on vehicle volumes per lane and lane occupancy. Data for this system are combined to provide an estimate of average speed per lane every 20 seconds. Corridor travel times are estimated from average speeds. Weekday travel times are computed for a start time every five minutes.
- Manual data collection is used to obtain vehicle-occupancy and bus ridership information. Periodic surveys of HOV lane users, drivers in the general-purpose lanes, and the general public are also conducted.
- Vehicle-occupancy data is collected by visual inspection. There are 15 routine data collection sites. These sites cover all corridors with HOV lanes. The sites are selected so that staff can safely stand and sit. The sites must also have good sight lines into passing vehicles to count occupants. Data are collected in the morning and afternoon peak periods during times of the year when is it light enough to observe the number of occupants in a vehicle.
- Data are collected six times a year at each of the 15 primary locations and the six supplementary locations. Data for the HOV and general-purpose lanes are counted separately for the morning peak period and the afternoon peak period. A more limited number of midday counts are conducted at fewer locations.
- Bus ridership information is obtained from transit authority passenger counts. Ridership on specific routes at specific locations is requested. Four different transit agencies in the region provide this information. The transit authorities may use automated passenger counters or other methods to collect this information.
- Public opinion surveys are conducted on a periodic basis. Mail out/mail back surveys have been used with HOV users and motorists in the general-purpose lanes. Surveys of transit riders are conducted by handing out the questionnaires to passengers on buses and providing a pre-paid, return envelope. The response rate for these surveys typically averages around 20 percent or above.
- Data analysis of current conditions includes calculating person and vehicle volumes, travel times, and mode split. The travel times for the general-purpose lanes and the HOV lanes are compared and the 90th percentile speed is calculated for comparison against the performance policy.
- Examples of data analysis of current conditions include graphing daily HOV volumes, graphing weekday HOV and general-purpose volumes per lane, and graphing weekday volume, speed, and reliability conditions for the HOV and the general-purpose lanes. Comparisons are also made of the person and vehicle volumes per lane for the HOV and the general-purpose lanes. The AVO is calculated for the HOV and the general-purpose lanes.
- As an example, the travel time reliability versus policy standard analysis on the I-405 HOV and freeway lanes indicates that the speed reliability threshold of 45 mph is not met approximately 10 percent of the time. A comparison of HOV and general-purpose travel times on the southern half of I-405 in the northbound direction of travel indicates that the average travel time savings in the HOV lanes during the morning peak period is approximately 11 minutes.
- Trends in the different performance measures are also tracked. For example, trends in travel time and trip time reliability are monitored to identify any HOV lanes not meeting the performance measures.
- A variety of methods are used to report the results of the performance monitoring activities. Paper reports are prepared on current conditions and trends. Internet-based publishing of key statistics is being used more, however, to reduce the number of printed reports.
- Data sets are available on two websites — http://trac29.trac.washington.edu/tracmap/mapserver and http://trac29.trac.washington.edu/hov/. These websites provide a map showing the HOV lane segment and data collection sites, the basic characteristics of the site, and the number of data collection sessions at each site. The sites also provide the capability for users to analyze and map the data.
- These websites are still in the development stage and there are a few issues that need to be addressed with the use of the website. The first issue is spreading the word about the website's existence. Data quality represents a second issue. Meta data, including what data exists, how the data can and should be used and not be used, and how the exportable data files are organized represent other issues. The site usability may also be an issue.
- The current concept and status design concept includes two levels of data. The first level contains common summary statistics. The second level database provides access to raw statistics. Contact information is provided to help with learning about using the database and to help with learning about the data itself.
- Currently three databases are connected through TRACMap. These databases are the average car occupancy (ACO) database, the freeway operations or FLOW database, and commercial vehicle information system network (CVISN) tag-based travel time database. The ACO database is a working prototype. Currently, summary statistics are available. The user interface, summary statistics, and meta data need refinement, however. The FLOW database is also a working prototype, with summary statistics available. On-line access to raw data is not currently available, as the legacy system needs updating. The user interface also needs considerable work and the meta data are under refinement.
- The report website, which presents summary statistics via the Internet, rather than paper reports, is under development at http://depts.washington.edu/hov/. Summary statistics already exist, but an issue is how to highlight trends.
Eleven Things You Should Know about the Carpool Lanes in Los Angeles County
Darren Henderson, Parsons Brinkerhoff
Darren Henderson discussed the HOV Performance Monitoring Program sponsored by the Los Angeles County Metropolitan Transportation Authority (MTA). He described the major elements of the study and the executive summary, which is presented in a brochure highlighting the 11 key findings from the study. The executive summary has been distributed to policy makers, interest groups, and other key stakeholders.
- The MTA HOV Performance Program included four major elements. These elements were to define the HOV performance goals, to create a comprehensive database on the HOV lanes in the county, to evaluate the performance of the HOV lanes, and to assess the public support.
- The HOV system in Los Angeles County includes 382 lane miles on 14 freeways. Most of the HOV lanes are buffer separated with limited ingress and egress. A 2+ vehicle occupancy is used on all the HOV lanes, except the El Monte busway, which uses a 3+ requirement in the morning and afternoon peak periods. The HOV lanes operates on a 24/7 basis.
- The executive summary report for the HOV Performance Monitoring Program focused on the 11 things you should know about the HOV lanes in Los Angeles County. The 11 points are presented, along with graphics supporting the elements and providing additional information.
- First, nearly everyone supports the HOV lanes. A total of 89 percent of the respondents in the general public survey indicated they supported having HOV lanes on Los Angeles County freeways.
- Second, all carpool lanes save time, and the time savings can add up. The actual time savings varies by HOV lane, with the greatest time savings provided by HOV lanes on very congested freeways.
- Third, carpool lanes do not have to look full to be effective. Even with capacity constraints and fewer vehicles, an HOV on a congested freeway carries one to three times more people than an adjacent general-purpose lane.
- Fourth, carpool lanes are used all day, everyday. The use of the HOV lanes is highest during the morning and afternoon peak periods, but travelers use the lanes throughout the day and on weekends. Approximately 40 percent of daily HOV lane use occurs outside the peak periods.
- Fifth, carpool lanes encourage people to switch from driving alone. Survey results indicate that approximately 50 percent of current carpoolers using the HOV lanes formerly drove alone on the same freeway. An additional 9 percent reported driving alone on a parallel street or another freeway.
- Sixth, carpool lanes are a good public investment. Considering only the benefit of time savings, approximately half of the HOV lanes in the county have proven their economic benefit.
- Seventh, many carpool lanes are full and have no capacity to sell. Approximately 10 of the 16 HOV lanes in the county carry between 1,200 and 1,600 vehicles per hour during the morning and afternoon peak periods. Thus, there is little or no capacity available for other potential user groups.
- Eighth, carpool lanes are important to bus transit. The El Monte Busway and the Harbor Freeway Transitway carry significant volumes of buses and bus riders. Some 24,000 daily passengers ride buses on the El Monte Busway and the Harbor Transitway carries approximately 5,000 daily riders. Further, some 83 percent of the bus passengers surveyed indicted the availability of the HOV lanes was very important in their decision to ride the bus.
- Ninth, there are not a lot of cheaters in the carpool lanes. Violation rates on the HOV lanes in the county are low, averaging at or below 3 percent. CHP provides visible enforcement and the $271 minimum fine helps discourage violators.
- Tenth, carpool lanes can help air quality. Analysis indicates that the HOV lanes generate about half the emissions per person mile than the general-purpose lanes. Survey results also indicate that residents feel the HOV lanes help the region's air quality.
- Eleventh, just because the traffic is backed up in other lanes does not mean the carpool lanes are not working. Although some HOV lanes do experience congestion, they still provide mobility options to travelers. Further, survey results indicate that some 64 percent of the respondents agree or strongly agree that the HOV lanes help reduce congestion in all the freeway lanes.
What Information Does the Press and Public Want?
Lucas Wall, Houston Chronicle
Lucas Wall discussed news stories on HOV facilities in the Houston Chronicle. He highlighted the focus of recent news stories and summarized the types of questions received from readers on the Houston HOV lanes. He also provided suggestions for transportation professionals on interacting with the print media.
- Over the past two years the term HOV has appeared 60 times, or about three times per month, in by-line stories. Overall, HOV appeared 239 times in Chronicle articles over the two-year period, for an average of about 10 times per month.
- The articles on HOV facilities have covered a wide range of topics. Articles have addressed the HOT lane concept, hours of operation, and a timed test of different commuting methods. Other articles have provided profiles of casual carpoolers, vanpoolers, and carpool promotion month. Plans for HOV lane extensions, construction updates and construction impacts on traffic, the HOV component of the 2025 transit plan, and bus/automobile crashes have also been featured. Managed lanes, toll polices, and enforcement and fine collection have been discussed in articles.
- The Monday Chronicle features a column on answers to readers' questions on transportation. Many of the questions sent in by readers focus on the HOV facilities. Many readers ask why Houston has HOV lanes. Approximately 74 percent of Harris County commuters travel to work by driving alone and the vast majority of commuters get no perceived personal benefit from the HOV lanes. There is some skepticism about why the lanes exist — these solo drivers want that pavement for their use.
- Readers also ask about the design of the HOV lanes and why there are barriers separating the HOV lanes from the general-purpose lanes. Houston has a unique form of HOV lane and the public has trouble understanding that the lanes were originally designed primarily for buses and vanpools. The HOV lanes are not seen as flexible enough to many readers, with not enough entry and exit points for carpools.
- Readers also express concern about enforcement of the HOV lanes. There is a perception that SOVs are using the HOV lanes. The public complains that they rarely see METRO police enforcing the vehicle-occupancy restriction, especially the concurrent flow lane segment on I-10 West. There is a belief that the HOV lanes are not successful if there is no enforcement. Even commuters who do not like the HOV lanes seem to want strict enforcement as they do not want someone else getting a quicker trip by cheating.
- Other questions asked by readers concern how to use the HOV lanes. Infrequent users are not sure where to enter and exit the lane. There is an insecurity about where a lane goes and how to exit. The need for better signage is a frequent request from readers. Other typical questions focus on operating hours and why the lanes are not open 24 hours a day and on weekends. Readers also ask why the HOV lanes are not bidirectional and why lanes are closed during lunchtime.
- One thing transportation personnel responsible for HOV lanes can do is provide information on the role the HOV lanes play in enhancing mobility and in moving more people in fewer vehicles. There is a need to convince solo drivers that the HOV lanes serve an important purpose and that they do benefit from getting vehicles out of the general-purpose lanes. Providing monthly or quarterly information on the number of HOV users — bus riders, vanpoolers, carpoolers, and motorcycles — is a good way to keep reinforcing the benefits of the lanes. Providing information on the average travel speeds in the HOV lanes versus general-purpose lanes is also important. Give meaning to the numbers — "If we did not have this HOV lane, X vehicles would be added to the mainlanes, which would drop the average travel speed to X mph, resulting in an average of X minutes of delay for every commuter in the corridor."
- Transportation professionals also need to explain the design and operation of the HOV facilities. Help the public understand the importance of the HOV lanes to buses and the transit system in Houston. Compare the functionality of a concurrent flow lane versus a barrier-separated lane and explain the pros and cons of different approaches. Note the ease of enforcement in barrier-separated lanes as a benefit of this approach.
- Focus on enforcement. Include the number of tickets issued and other enforcement information in the monthly or quarterly updates. Report the results of spot checks of violators versus authorized vehicles highlighting the percentage in compliance. Media ridealongs are a good way to involve reporters. Plan an intense week of HOV enforcement and bring reporters and photographers along.
- Market how to use the lanes through brochures and websites. Smarter signage is needed and the use of circuitous routes to reach an HOV lane should be eliminated. Take reporters on a facility tour, show them the system, and explain how it is designed and how it operates.
- Help reporters understand traffic counts and how the hours of operation are set. Demonstrate the costs of extra operating hours in terms of extra staff and police personnel. Explain the cost for each additional hour and provide a cost/benefit analysis. Keep the public informed of expansion plans, studies on HOT lane expansion, bi-directional studies, and other projects.
- It is important to remember that a majority of people drive alone and are skeptical or resentful of efforts to exclude them from something they are paying for. As a result, be sure to completely explain and profile HOV projects, and note how HOV lanes benefit drivers in the general-purpose lanes.
- Reporters love numbers, facts, and statistics — but they need to be comprehensible. Reporters do not like to have to do math and calculate statistics for themselves. You can help write your own story by presenting easy-to-understand facts that capture the advantages of HOV lanes. Make your public relations active, not reactive, provide information to reporters and facility tours. Do not wait for a problem to occur and a negative story. Rather be proactive in providing needed information on HOV lanes.