Chapter 4: Infrastructure Improvements for Older Road Users

Standards and Guidelines

As in the United States, the consensus standards development process in Australia and Japan is time consuming. Best practices and established engineering solutions may appear in guideline documents years before they are incorporated into state or federal design standards. This implementation lag is present in the United States as well. The recommendations of the FHWA Older Driver Highway Design Handbook are just now appearing in the Manual on Uniform Traffic Control Devices for Streets and Highways (MUTCD) and A Policy on Geometric Design of Highways and Streets (AASHTO Green Book), even though the original handbook is more than a decade old.

Austroads is the association of Australian and New Zealand road transport and traffic authorities, so it functions much like AASHTO does in the United States. Austroads has sponsored research and policy development to identify infrastructure improvements for older road users. ⁽³³⁾ This major research effort, titled Environment and Design for Older Drivers, was conducted by researchers at Monash University Accident Research Centre under the sponsorship of Austroads. Stage one of the research, conducted in the late 1990s, used the FHWA Older Driver Highway Design Handbook as a guide to evaluate the state of Australasian roads (encompassing Australia and New Zealand). ⁽³⁴⁾ This effort also included site visits to "black spots" with a higher-than-normal involvement of older drivers in accidents. The site visits concluded that intersection sight distance and gap acceptance were particular problems for older drivers. The second phase of this project, completed in 2004, includes a large roadway design handbook with points to consider when designing roads to accommodate older road users. ⁽³³⁾ A training workshop was also developed and efforts are underway to incorporate these recommendations into Australasian road design standards. In general, it appears that Australia has followed the FHWA model very closely on handbook and training course development paired with changes in existing standards to better address the specific needs of older road users.

The Japanese Industrial Standards address some infrastructure elements such as roadway lighting and accessibility for disabled people. The roadway lighting standard has been influenced by research on the visibility of elderly pedestrians. ⁽³⁵⁾ The accessibility standards, similar to Americans with Disabilities Act standards in the United States, also serve the needs of older road users by specifying curb heights, tactile markings, and sidewalk widths to aid older people with mobility limitations.

Institutional Issues in Implementing Infrastructure Changes

Jurisdictional Funding Priorities

As in the United States, the countries visited have a stratified level of government, each with its own spending priorities and political pressures. The Japanese example cited in Chapter 3 on local agencies' desires for infrastructure changes that affect the aesthetics and livability of their towns demonstrates this.

In Australia, the strategic safety plan is used to unify all levels of government on project selection and funding. As mentioned in Chapter 2, the involvement of political officials from all levels of government in developing and adopting the strategic safety plan can prevent some of these conflicts. At a state government district office level, the national or state safety plan can be used as a defense against politicians and citizens who may be promoting infrastructure changes that will have a smaller impact on safety. In addition to the safety plan, crash data and projections can also be used to defend priorities.

Cost-sharing plans that give local governments direct control over a portion of state or federal aid money are another tool used to encourage improvements on local roads. The Japanese federal roads agency has used crash data to demonstrate safety problems on local roads to local governments. It then offers to improve regional arterial systems to pull traffic off the local roads, reducing traffic volumes and exposure on the local roads. This traffic diversion enables local governments to establish lower speed limits in residential areas, enhancing pedestrian and bicycle safety.

Some local governments may be reluctant to participate with state or regional partnerships because they view roadway issues as state issues and fear that maintenance costs may shift to them. Good communication between local and state district officials is important to assuage those fears. Professional societies and formal partnerships such as the Road Alliance can also promote interaction and information sharing.

Regional Coordination and Partnerships

Coordination of design and operations standards, maintenance activities, and construction on a regional level is important to provide road users with a predictable system. This predictability in and of itself can enhance safety by easing the driving task. Local preferences for certain infrastructure elements that provide a local identity such as street name sign design, crosswalk markings, or roadside landscaping can often interfere with the goal of uniformity. Formal partnerships such as the Road Alliance in Queensland offer one way of encouraging coordination and cooperation by providing a means for local agencies to share resources, such as sign maintenance contracts that save money for the agency but also provide uniformity on regional roadways.

Design Flexibility

A flexible approach to roadway design standards, similar to the U.S. resurfacing, rehabilitation, and restoration (3R) standards, was discussed at Queensland Main Roads. This concept, known as the Extended Design Domain, allows roads to meet different minimum design criteria as long as there is no known negative safety record. This flexibility in design criteria allows rehabilitation improvements to be made without bringing the entire roadway up to current design standards. It also allows funds to be spread across multiple lower-cost improvements on a systemwide basis rather than dedicated solely to one expensive countermeasure. If the roadway serves areas of high use by older drivers, as determined by local authorities, these extended design criteria cannot be applied and the road must meet the highest current standards.

The scan team observed other examples of flexibility in roadway design in many of the urban areas it visited. Innovative pedestrian treatments were applied in locations judged by local engineers to be areas of high pedestrian traffic. In other cases, countermeasures were installed based on crash history. Systemwide transit boarding area improvements were being phased in where right-of-way allowed. In some cases, traffic lane shifts and parking restriction changes were necessary to accommodate the wider boarding areas.

Implementation Examples

The FHWA Older Driver Highway Design Handbook ⁽¹³⁾ and the subsequent Australian modification of it ⁽¹²⁾ were the basis for most of the roadway improvements observed in Australia. Many of the improvements implemented, particularly those at intersections, focus on removing the go/no-go decision from the driver.

Intersection Operations and Design

Figure 8. Protected right-turn signals in dedicated right-turn lanes in Melbourne (equivalent to left turn in the United States).

For urban intersections, the most common improvement was to add a protected right-turn (left-turn in the United States) phase and add a turn arrow to the signal head. This improves safety for all drivers, but especially for seniors, who have historically high crash rates in these situations. The addition of a dedicated turn lane also aids older drivers by removing them from through traffic. More important, it offsets them laterally to provide better visibility of oncoming traffic. As figure 8 shows, the signal head is mounted overhead and on the center median island to further enhance visibility.

Another area of infrastructure improvement aimed at older road users in Australia was roadway and roadside design criteria changes. Examples from geometric design were adjustments to intersection angle and merge lane length that would differentially aid older drivers by reducing the amount of head turning needed to navigate intersections and merge areas. For older drivers, a more perpendicular crossing also reduces the need for extreme head turns, which can be difficult for those with arthritic necks and shoulders.

The slowing response times of older drivers were reflected in allowing longer perception reaction times in formulas for intersection sight distance and stopping sight distance. Many of the adjustments to these parameters were adapted from the FHWA Older Driver Highway Design Handbook. ⁽¹³⁾

Traffic Control Devices

Figure 9. Median barrier treatments and pavement marking text in Tokyo.

As with most other safety improvements, changes in traffic control device standards aid all drivers, not just older drivers. Traffic control device standards in Australia require high-brightness sign sheeting and pavement marking materials to ensure good nighttime visibility for older road users. ⁽³⁶⁾ Some agencies use larger signs and wider markings to further this aim, but no standards are in place for these applications.

In Japan, horizontal curves on expressways are enhanced through the placement of retroreflective materials on concrete median barrier walls and guard rails, as figure 9 shows. The Japanese also make widespread use of text and symbols in pavement markings. The text used on expressways shown in figure 9 lists a destination city name before a major interchange.

Pedestrian Facilities

Both countries presented further examples of infrastructure improvements aimed specifically at pedestrians. These changes would especially benefit older pedestrians because of their large over-representation in severe injury and fatal crashes involving a motor vehicle and a pedestrian.

In Japan, a strong theme driving many changes to infrastructure is the physical separation of pedestrians, bicyclists, and motor vehicles. This is accomplished through sidewalk widening, dedicated barrier-separated bicycle facilities, and pedestrian grade separation at large, busy, multilane intersections (either overpasses or tunnels). Figure 10 (see next page) shows the street-level entrance to an underground pedestrian tunnel under a busy urban intersection in Tokyo. Even where barrierseparated bicycle lanes cannot be built, traffic control devices encourage separate travelways for these modes (see figure 11 on the next page, in which the text in the foreground reads "stop" and the text within the lane lines reads "bicycle"). These separations provide an added measure of protection from vehicles for vulnerable road users. In addition, Japanese officials reported some injuryproducing collisions between bicyclists and pedestrians. The separation of bicycle and pedestrian facilities will help reduce those risks as well.

In Australia, pedestrians were also the focus of many infrastructure improvements. These improvements aid all pedestrians, not just older persons, by providing better visibility of the crosswalk to approaching vehicles. Figure 12 shows a raised crosswalk with curb extensions in Sydney. This design shortens the walking distance for pedestrians, reducing the time they are exposed to traffic. The curb extensions also bring the pedestrian closer to the travelway, making the waiting pedestrian more visible to approaching motorists. Figure 13 shows a shopping area that uses curbside fencing and landscaping to channelize pedestrians to the crosswalks. In addition to parking restrictions near crosswalks, the landscaping provides a mechanism to provide bump-outs that shorten the walking distance at the crosswalk. The median island signs and marking also improve the conspicuity of the crosswalk to approaching vehicles. Another example of pedestrian fencing is shown in figure 14. Melbourne also uses actuated pedestrian signals at midblock crossings in areas of high pedestrian traffic.

Figure 10. Underground pedestrian walkway under a busy urban intersection in Tokyo.		Figure 12. Raised crosswalk with curb extensions in Sydney, Australia.
Figure 11. A crosswalk in Tokyo with separate lanes for bicycles and pedestrians.		Figure 13. A pedestrian crossing with refuge islands and gates in Sydney, Australia.

Some cities, such as Melbourne, are making improvements to transit infrastructure to enable easy boarding and transferring for elderly and disabled riders. The transfer station located in the median of a suburban arterial street shown in figure 15 allows tram riders to exit the tram at the end of the line and board local buses without crossing the street. In general, after discussions with experts in both countries, the scan team believed that the low level of paratransit services was comparable to those in the United States. This was particularly true in rural areas. Both Japan and Australia have laws equivalent to the Americans with Disabilities Act, but it appeared that these laws had not been in place as long as the U.S. law.

Figure 14. Midblock pedestrian-actuated crossing with pedestrian fencing in Melbourne, Australia.

Colored Pavements

In both countries, the scan team noticed the frequent use of colored pavements for a variety of purposes. Australia used red to prohibit normal vehicular traffic from bus and taxi lanes (see figures 16 and 18) and green to emphasize bicycle lanes in high-hazard areas (see figure 17). Japan was experimenting with colored pavement to mark high-hazard horizontal curves. Crash data from one location shows a large reduction in run-off-road crashes, particularly for large trucks. Japan was also experimenting with using colored pavement as a tool for positive guidance and lane assignment through complex intersections. In lane guidance applications, the colored pavements match the colors of route legs shown on accompanying diagrammatic signs. This could be particularly advantageous to older drivers, especially in decreasing decision time at information-rich locations. Australia reported some recent developments in materials with durable color and sufficient pavement friction to not pose a safety hazard to pedestrians and cyclists. While these materials appear to show promise, thorough evaluations of material durability and driver behavior have not been completed. This is an area for future research in the United States.

Figure 15. Tram-bus transfer station in Melbourne.		Figure 16. Red-colored pavement used to mark a bus queue-jump lane at a signalized intersection in Melbourne, Australia.

Figure 17. Green-colored pavement used to highlight a bicycle lane as it crosses an unsignalized intersection in Sydney, Australia.		Figure 18. Bus lane with red pavement on the Sydney Harbor Bridge.