This report summarises the results from the second sub-trial of a larger track trial investigating the reactions of road users to Low Level Cycle Signals (LLCS) under different junction configurations. In this trial the LLCS were positioned on the same pole as the standard traffic signals and gave an ‘early release’ for cyclists ahead of the vehicle traffic. The trials were conducted at a specially constructed typical “urban” four-arm junction built at TRL’s test track. The trial consisted of “control” and “treatment” experiments, with four different durations of early release in which the LLCS changed to green 2, 3, 4 or 5 seconds earlier than the main signals. These were then compared to the previous trial of LLCS with no early release to understand the relative effect on behaviour of the early release. Trials were conducted for three different road user groups over 7½ days, with a total of 200 participants: cyclists (4½ days); car drivers (2 days); and motorcyclists (1 day). Key findings are listed at the end of each sub-section and are referenced here in square brackets. In summary: 1. Almost all participants (more than 95%) in all road user groups understood that LLCS were traffic signals for cyclists [F1.a]. A small minority of cyclists (2%) were initially confused and said they took a while to understand how to use the early release [F1.b] and a small minority (<1%) of cyclists confused the LLCS with a Toucan crossing, although this was less than in the trial with no early release [F1.c]. 2. When asked specifically about the early release, all the car drivers and about 95% of cyclists and motorcyclists said they noticed it [F2.a] and over 80% in each road user group were positive about it [F2.b]. About 15% of cyclists and 5% of car drivers and motorcyclists were negative about the early release with the most common reasons being ‘Found the junction to be confusing’ and ‘Concern that it would delay motorists’ [F2.c]. 3. Over 90% of participants thought that cyclists on the road would benefit from LLCS, which was similar to the trial with no early release [F3.a]. About 90% of cyclists and car drivers and 75% of motorcyclists were positive about LLCS in general, which was higher compared with the trial without an early release [F3.b]. Over three-quarters of the cyclists said that the height of the LLCS was ‘about right’ and about 60% of cyclists thought the angle was ‘about right’. About 10% of cyclists described turning right as ’difficult‘ due to the angle of the LLCS and not being able to see the junction and the signal at the same time [F3.c]. 4. Cyclists looked at the LLCS more than the trial with no early release [F4.a] and the LLCS were the most important source of information for the majority of cyclists [F4.c]. 5. The early release had no effect on compliance with the red signals [F5.a] or on compliance with the stop lines [F5.c]. 6. A large majority of cyclists started moving as the LLCS changed to red and amber [F6.a] and the cyclists entered the junction approximately 1.5 to 2 seconds after the LLCS changed to green [F6.e]. Combining the findings from the cyclist trial and car trial suggests that a cyclist would enter the junction ‘on average’: 3.5 seconds before a car would enter the junction with a 2-second early release; 4.5 seconds ahead with a 3-second early release; 5.5 seconds ahead with a 4-second early release; and 6.5 seconds ahead with a 5-second early release [F6.g]. Some motorists started moving before the main signals changed to red and amber [F6.b], and when asked what they would do in the real world some said they would do this or ‘it depends’ [F6.c]. 7. A longer early release resulted in a larger proportion of observations where the cyclist turned right in front of the oncoming car, ranging from 24% for the 2- seconds early release up to 69% for the 5-seconds early release [F7.a]. The most common explanation was that they thought they had enough time, although a few (5%) thought they had right of way [F7.f]. 8. Typically for each second of early release, the average Clearance Time decreased by one second [F8.a]. A higher proportion of cyclists said the junction was ‘safer’ or ‘much safer’ than an ordinary junction in the trial with an early release (about 85%), compared to the trial without an early release (about 50%) [F8.b]. A small proportion of cyclists (5%) said that the early release made the junction less safe, because of other road users using the early release and confusion over right of way when turning right [F8.c]. The evidence from this trial supports the progression to on-street trialling of LLCS with an early release. The evidence suggests that the system would be quickly understood by nearly all road users, would not adversely affect safety and could offer a benefit to cyclists in getting up to speed, clearing the junction ahead of motorists and feeling safer. The only caveats are that a small proportion of cyclists thought they had right of way when turning right across oncoming traffic and some motorists started moving before the main signals changed to red and amber. (Author/publisher)
Abstract