Full Technical report - EyesOnStripes (Final)
Full Technical report - Final draft
Executive summary
The main purpose of this proposal is to convince The Land Transport & Authority (LTA) in the need to address the high accident rates in Singapore’s slip road pedestrian crossings, which is caused by ineffective road markings.
EyesOnStripes has decided to propose the use of traffic calming markings (TrCM) to alert drivers about the pedestrian crossings ahead and have them react in an appropriate manner. TrCM can be seen as a preventive measure to reduce the risk of collision among road users.
TrCM is feasible and the key stakeholders including the pedestrians, drivers and LTA can benefit from this implementation. The overall safety at a slip road zebra crossing will improve with TrCM.
1. Introduction
1.1 Background
This proposal has been developed during a module in Singapore Institute of Technology (SIT) to define a local problem in the infrastructure sector, which has been identified to be the safety issue on the road of Singapore. Iskandar Bin Khairuldin who is a member of EyesOnStripes, has thirteen years of experience as a traffic engineer in the Land Transport & Authority (LTA).
He states that Singapore faces high accident rates among road users, and received many feedbacks that questions the road safety in Singapore. According to Budget Direct Insurance (2020), there were “7690 road accidents involving injuries in 2018”, and “fatality rate of 2.73 per 100,000 citizens is higher than London, Hong Kong and Tokyo”. This study shows that Singapore has a high accident and fatality rate when comparing with other cities of a similar size population. There is a need to address this problem at high-risk zones which Iskandar claims to be at slip road zebra crossings.
He further states that ineffective markings at slip road pedestrian crossings result in inattentive drivers. A reaction that is expected from the drivers when they see the zig zag and dashed white markings at the crossing would be for them to be alerted, and then slow down as they drive through the markings. A marked crossing does not resolve in a safer road environment when the markings are ineffective. According to the US Department of Transportation (2005), a marked crosswalk had 37 crashes while an unmarked one had 23 crashes. This can suggest that there is a need to reinforce the markings at the slip road crosswalk.
EyesOnStripes has decided to implement striking and clear markings that will be painted onto the lanes of the slip road crosswalk. Traffic calming markings (TrCM) are triangular road markings painted in pairs along the lane. TrCM will induce the motorist to slow down due to the narrowing effect. As reported by LTA (2013) in a conference report, TrCM is effective to reduce the road speeds. TrCM is a clear road marking that can create an ideal slip road zebra crossing that can have drivers to be alerted and slows down when approaching the crosswalk.
1.2 Problem statement
The current slip road zebra crosswalks in Singapore include zig zag and dashed markings. These markings do not catch the attention of the motorists, as it fails to effectively alert and have them to slow down as they approach the crossing. The risk of collision among road users will increase when the driving speed is not reduced, which is a significant reason that contributes to the high accident rates in Singapore.
This proposal aims to implement traffic calming marking (TrCM) and yellow checkered markings to warn drivers to be vigilant about the crossings ahead and prompt them to slow down.
The purpose of this proposal is to convince the Land Transport & Authority (LTA) of the need to implement TrCM and yellow checkered road markings onto the crossing to improve safety levels on the roads.
2. Proposed solution
The team aims to adopt clear and distinct traffic calming markings (TrCM) or otherwise known as the dragon tooth markings. It is used to alert drivers with the use of narrowing effect which gives drivers the perception that the road is narrowing as they approach the crossings. Drivers will then have enough time to react as they slow down which can prevent collision among road users.
LTA (2009) has claimed to have tested traffic calming markings (TrCM) at three different streets in Singapore. The report also mentioned that 64% of those surveyed showed to have slowed down with a reduction in driving speed of 10%.
The proposed solution as shown in figure 1, the TrCM will be painted at the start of the slip road, approaching the zebra crossing with interval distances between each marking.
Figure 1. Traffic calming markings on slip road zebra crossing
3. Benefits of traffic calming markings (TrCM)
TrCM has shown to be both feasible and viable in its implementation. According to Montella et al. (2011), implementing the TrCM will be more feasible when stakeholders are more likely to implement the solution as it has shown its efficiency in speed reduction while minimising resources needed.
3.1 Reduced cost
The first and most significant benefit of having TrCM is a significantly high reduction in cost when comparing to other existing solutions such as repavement. Based on Iskandar’s previous project, the proposed TrCM solution will cost approximately $1800 when implemented on lanes illustrated in figure 1, whereas existing solutions such as completely repaving a 10m length of road as illustrated in figure 2 would have a higher estimated cost of $50,000.
Figure 2. An example of road repaved before a signalised pedestrian crossing
The second important benefit of having TrCM is the significant reduction of time needed for complete implementation of TrCM over existing solutions such as repavement. Iskandar has estimated that the painting and drying of dragon teeth markings only requires six hours, versus the longer duration of 3 days needed to complete repaving the 10m length of road as shown in figure 2.
3.3 Reduced manpower
The third benefit of having TrCM is the reduced manpower required for completion of road paintings in comparison to existing solution of repavement. According to Iskandar, the proposed TrCM solution will require 4 workers to complete, as compared to 8 workers that will be needed for the alternative solution in repaving the 10m length of road shown in figure 2.
3.4 Easier implementation and maintenance
Lastly, it is important to not only consider the tangible benefits but also the intangible advantages the TrCM can bring. For instance, implementation and maintenance will be easier in the long run, over existing solutions such as repavement. According to Iskandar, the proposed TrCM solution does not require sophisticated construction machinery during implementation and maintenance in the long term, unlike alternative solutions such as the repavement shown in Figure 2.
3.5 Pedestrians and drivers
The team has identified three key stakeholders to ensure the viability of the implementation. These stakeholders are the pedestrians, drivers and LTA. TrCM is effective to alert drivers and have them to react by slowing down. The dragon teeth marking can act as a preventive measure to reduce the overall risk of collision among road users. Pedestrians and drivers will have safer road environments.
3.6 LTA
As the overall risk of collision at the slip road zebra crossings is decreased, there will be lesser casualties which LTA will have lesser cases to attend to.
3.7 Effects and Plan of Action
All key stakeholders are expected to take measures for an effective implementation. As illustrated in appendix A, LTA are to establish the markings and to consistently monitor and maintain the viability of TrCM. Traffic Police (TP) shall continue their role in enforcing regulations, investigating the causes and contributing factors when collisions appear, and at the same time educate the public. By doing so, LTA and TP will have fewer accidents to attend to. The general public are to remain alert and not rely solely on the markings.
The team has identified a total of three potential challenges that need to be addressed.
4.1 Challenge faced if using LTA design
The first challenge TrCM will face is the distance constraint when using the LTA design. Figure 3 shows the design that LTA uses to implement the dragon teeth on straight roads. It is painted over a distance of 53m with a decreasing interval from 8m to 2m. However, most lanes on slip road zebra crossings in Singapore are shorter than 53m, as shown in figure 4. Therefore, it is not feasible to implement the design LTA used.
Figure 3. LTA standard on dragon teeth on straight roads
Figure 4. Standard slip road with existing road markings
The second challenge faced when using LTA design is the LTA standards on the dragon teeth marking’s size. Referring back to Figure 4, the existing markings include white zig zag and dotted lines. These markings increase the difficulty to adopt the TrCM due to space constraints.
According to the LTA standard (2009) in Figure 5, it shows that dragon teeth must have a minimum 1.5m distance between the two opposite sides. Referring back to Figure 1 that shows our proposed solution, it has failed to meet the 1.5m requirement.
Figure 5. Dimensions of dragon tooth
Solution: Improvising on the LTA design
The two challenges can be resolved by improvising on the design from LTA. The new design will not have the distance decreasing in interval, and will only have one dragon tooth on the zig zag side of the crossing shown in Figure 6, which resolves both distance and space constraints.
Figure 6. Left side of the road to have 1 dragon tooth
4.2 Visual appeal
The third challenge is the low visibility of TrCM which can result in drivers ignoring the road markings. Existing markings can overshine the dragon teeth. Figure 7 shows the new design with the current markings and TrCM painted in white. As shown, the dragon teeth are barely seen.
Colour is an aspect of road markings that could potentially improve the effectiveness in the road markings. According to Lee, et al. (2013), TrCM has shown a significant decline in driving speeds, but colour was an aspect to be looked into for improvements.
Figure 7. Slip road zebra crossing with white TrCM (not drawn to scale)
Solution: Yellow TrCM
The team decided to paint TrCM in yellow. Figure 8 shows the newly proposed design having the dragon teeth in yellow.
Figure 8. Slip road zebra crossing with yellow TrCM (not drawn to scale)
Enhancing narrowing effect: Yellow checkered markings
As drivers slow down due to the narrowing effect of TrCM, the yellow checkered marking can enhance this effect with the role of being the “obstacle”. This can further slow them down as they will want to avoid collision with the “obstacle”. Figure 9 shows the picture of one side of the crossings is painted with yellow checkered markings which is currently a 3m empty space.
Figure 9. Yellow checkered markings between stop line and zebra crossing
The team has decided to implement TrCM without the distance interval and to be painted in yellow. Yellow checkered markings are used to enhance the narrowing effect of TrCM. By overcoming these challenges, TrCM will be much more visible and effective. Drivers will pay closer attention and slow down. Thus, reducing overall collision risk and providing an overall safer road to the general public. Appendix B shows a detailed illustration of each marking as proposed in our implementation.
Figure 10. Final TrCM implementation plan
5. Methodology
The methodology of this proposal is based on both primary research and secondary research.
5.1 Primary Research
The primary research for this project was in the form of an experience by an LTA traffic engineer, Iskandar Bin Khairuldin, a member of this team. As a traffic engineer, Iskandar resolves public feedback involving traffic issues. While encountering public feedback, Iskandar and his colleagues realised that feedback towards road slip accidents are becoming more prominent. However, there was no new solution available for them to combat this issue as road markings and road signaling devices are already in use on roads.
An Interview with a member of LTA was also conducted. Norashikin Mohammed Ali, the manager of Traffic Scheme Design Development Division (TSDD) of Traffic and Road Operations, supported our proposal and has given valuable insight on the implementation, as shown in appendix C.
5.2 Secondary Research
The main source of secondary research is a review of a series of articles. Some of the articles included a report of an overseas conference conducted by LTA and research journals detailing the effects of TrCMs on motorists. A handbook published by Traffic Police titled “Basic theory of driving” was also used to gather information about existing road markings.
6. Concluding Statement
Due to Singapore’s high road fatality rate, EyesOnStripes has decided to mitigate risk at slip road zebra crossings. In doing so, the team has identified that the current markings are ineffective which causes drivers to not decelerate at a slip road zebra crossing.
The team proposes to adopt TrCM as a preventive measure to reduce the risk of collisions among road users, given the low cost, manpower and time needed for both implementation and maintenance in the long term as compared to alternative solutions. For a more effective result, yellow checkered markings are used to enhance the narrowing effect.
The three challenges identified can be addressed by painting TrCM in yellow with an improvised design of the dragon teeth. The key stakeholders identified are the general public, who can utilize the crossing with an ease of mind after the implementation. The LTA and TP will have fewer accidents.
With effective implementation of TrCM and yellow checkered markings, the visibility of road markings will be clear to drivers and allow them to slow down. This can decrease the risk of collision among road users thus, improving overall safety in Singapore’s slip road zebra crossing.
7. References
Alkhatib, S. (2020). Fatal crash: Driver thought he ran over large bottle. The Straits Times. Retrieved Feb 20 2020 from
https://www.straitstimes.com/singapore/courts-crime/fatal-crash-driver-thought-he-ran-over-large-bottle
Budget Direct Insurance (2020). Road accident statistics (Singapore 2020). Retrieved Feb 20 2020 from
https://www.budgetdirect.com.sg/car-insurance/research/road-accident-statistics-in-singapore
Lee, J. H., Noh, K. S., Kim, J. M., & Choi, J. S. (2013). The Effects of Pavement Markings on High-risk Drivers' Speeds. International Journal of Highway Engineering, 15(1), 127-134. Retrieved from https://doi.org/10.7855/IJHE.2013.15.1.127
LTA (2014). Standard Details of Road Elements. Revision B (2017). Land Transport Authority.
LTA (2014). Traffic Calming Markings (TrCM). Internal LTA report: unpublished.
Montella. A, Aria. M, D'Ambrosio. A, Galante. F, Mauriello. F & Pernetti. M (2011). Simulator evaluation of drivers’ speed, deceleration and lateral position at rural intersections in relation to different perceptual cues. Accident Analysis & Prevention. 43 (6), 2072-2084. Retrieved from https://doi.org/10.1016/j.aap.2011.05.030
Wei, Y., Ng, J., Ho, S. T., & Palanisamy, C. S. (2013). An assessment on the effectiveness of traffic calming markings and alternative for speed regulating strips. In 16th International Conference Road Safety on Four Continents. Beijing, China (RS4C 2013). 15-17 May 2013. Retrieved from http://www.diva-portal.org/smash/get/diva2:759733/FULLTEXT01.pdf
US Department of Transportation (2005). Safety effect of marked versus unmarked crosswalks at uncontrolled locations. Retrieved September 2005 from https://www.fhwa.dot.gov/publications/research/safety/04100/04100.pdf
8. Appendix
Appendix A
Table depicting the plan of action by each stakeholder during the proposed implementation
Appendix B
Detailed illustration of proposed implementation on slip road zebra crossing
Appendix C
An Interview session with Land Transport Authority (LTA)
EyesOnStripes conducted an interview with Norashikin Mohammed Ali, Manager of Traffic Scheme Design Development Division (TSDD), Traffic and Road Operations. During the interview, she mentioned “Those low usage crossings where you don’t expect a lot of pedestrians, that is where traffic actually moves and don’t take notice of pedestrians. Your project will be useful for that kind of areas where there are not constant movement of pedestrians. Accidents are common at these areas. To make your project more obvious for the objectives, I think can be targeted to this kind of locations.”
Ms Norashikin has advised the team that the proposed yellow TrCM and checkered markings will be more effective if they are to be implemented at slip roads with low pedestrian activities where there are high tendency of motorist speeding and not stopping at zebra crossing. With the proposed TrCM and checkered markings, she hoped that it will change motorist behaviour, adjust their speed accordingly and obey traffic rules. She complimented our efforts and hoped that more students would step up to contribute their traffic improvement ideas to the agency.
Comments
Post a Comment