This study examined the effects of LED rectangular rapid-flash yellow beacons (RRFBs) in uncontrolled marked crosswalks in three experiments. In Experiment 1, the RRFB system was evaluated with a two- and a four-beacon system at four multilane crossings. Results showed a marked increase in motorist yielding behavior over the baseline for the two-beacon system and a small but statistically significant further increase with the four-beacon system. The second experiment compared a traditional pedestrian overhead yellow flashing beacon and a traditional side-mounted yellow flashing beacon with the RRFB system. The results showed that the traditional overhead and side-mounted yellow flashing beacons produced a minimal increase in yielding, whereas the RRFB system produced a marked increase in yielding behavior. A third experiment examined the effectiveness of the RRFB system at 19 sites in St. Petersburg, Florida, as well as three additional sites, two in the suburbs of Chicago, Illinois, and one in the Washington, D.C., area. Results indicated that baseline daytime yielding behavior increased from an average of 2% to 86% at the 19 St. Petersburg sites and was 85% at the 2-year follow-up. A time-series intervention regression modeling was employed that estimated the parameters of the model based on a double bootstrap methodology. The results of this analysis confirmed a highly significant level change following the introduction of the RRFB that showed no sign of decay over time. Similar results were obtained at the District of Columbia and Chicago suburb sites. Probe data collected after dark revealed an even larger effect with yielding levels at the middle to high 90% level.

Specific service signs provide motorists with business identification information along freeway approaches to interchanges. The Manual on Uniform Traffic Control Devices limits the number of these signs along an interchange approach to four and the number of logo panels per sign to six, although there are continuing requests to increase the number of panels allowed per sign. The present research evaluated specific service signs with four, six, or nine panels per sign and with all logo-based panels or all text-based panels. Participants were asked to determine whether a particular business was present on a sign. Mean reaction times indicated that for nine-panel signs, younger drivers took approximately 2.2 s to determine correctly the presence of a business, while older drivers took approximately 2.9 s. In considering drivers of all ages, an increase from six to nine panels brings mean reaction times from 1.8 s to 2.5 s for text signs and from 1.9 s to 2.5 s for logo signs. In a second task, participants were given 2 s to view each sign before reporting the businesses present on the sign. Participants reported three to four businesses on average, regardless of the number of panels on the sign. Considering the generally accepted standard that eye glances away from the forward roadway for greater than 2 s are unsafe, the study concluded that the benefit of providing more service information is presumably not great enough to outweigh the risk of information overload and driver distraction.

The countdown pedestrian signal (CPS) has been shown to be more intuitively understandable than other signals in the way that it communicates the amount of available crossing time at an intersection. The improved comprehension may result in better levels of service to pedestrians at signalized intersections. Survey research has shown that the traditional flashing don't walk (FDW) signal is poorly understood, with low levels of pedestrian comprehension. By contrast, comprehension of the CPS tends to be much higher: between 86% and 100%. The study reported here examined how well low-vision pedestrians could determine how to respond and when to cross with the use of a CPS alone and with a combination of CPS and FDW at 12-m (40-ft) and 30.5-m (100-ft) crossings. The results showed that low-vision pedestrians often found it difficult to determine the signal phase at a relatively broad crossing, but the removal of the FDW from the display had no negative impact on the decision to cross during the pedestrian clearance phase.

The purpose of this study was to examine differences in comprehension between the inclusion and elimination of the flashing “Don't Walk” (FDW) on the pedestrian signal during the countdown phase. In Experiment 1, 300 people were shown, on a tablet, a digital video display of the walk symbol, the “Don't Walk” symbol, the countdown pedestrian signal (CPS) plus the FDW, and the CPS alone. Results indicated that pedestrians were more likely to consider crossing if they judged they had enough time to cross with the CPS alone than with the CPS plus the FDW and that this effect held for males and females and across all age categories. Experiment 2 examined how well pedestrians could determine how much time they required to cross streets of various widths. Participants viewed a CPS and were told to start crossing when they felt they had just enough time to cross. Participants had little dif-ficulty judging the time required for 40-ft, 60-ft, and 80-ft crossings. Most pedestrians could discriminate the time required without making significant changes in their walking speed. Another interesting finding was that pedestrians walked faster than typically reported in most studies in which they were timed starting at the onset of the walk. This is likely because pedestrians may walk more slowly when they know they have more than enough time to cross.

As part of a proposed change in the Manual on Uniform Traffic Control Devices, the effects of removing the flashing “Don’t Walk” (FDW) signal from the countdown pedestrian signal (CPS) is being considered. Field research conducted 10 years ago found later pedestrian crossing finishing times when a CPS without the FDW was compared with a CPS plus FDW signal, although there was no increase in the percentage completing crossing after cross traffic was released. Results also indicated a slight decrease in pedestrians running during the CPS alone condition. The purpose of the present study was to replicate systematically the Singer and Lerner field research 10 years later while increasing the number of sites where data were collected (from two to four) and collecting baseline, treatment, and follow-up data at each site. Other differences for this study consist of including both one-way and two-way intersections, different speed limits, and different buffer times. Results of this study found statistically significant decreases in pedestrians who were still in the crosswalk when cross traffic was released at three of the four sites when the FDW was removed from the clearance phase. Additionally, an increase in the number of pedestrians running was detected at some of the sites during the CPS alone condition. Therefore, it does appear that removing the FDW signal from the CPS would result in an increase in the number of pedestrians who reach the opposite side of the crosswalk without interfering with cross traffic.