Signalized Intersection Level of Service Incorporating Safety Risk

Zhang, Lin; Prevedouros, Panos D.

doi:10.3141/1852-11

Cited by 42 publications

(47 citation statements)

References 14 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…They used space and flow rate as parameters for defining LOS. Recently, [100,168,170,172] also used qualitative method; and considered parameters like delay, right-turn volume, platoon size, age and direction of travel in developing LOS. Pearson correlation and stepwise multivariable regression analysis using SPSS software were used to relate the parameters.…”

Section: Crosswalk Facilitymentioning

confidence: 99%

“…Pearson correlation and stepwise multivariable regression analysis using SPSS software were used to relate the parameters. In the USA, [170] developed a methodology which could quantify potential conflict between left-turning vehicles and opposing through vehicles with pedestrians. Delay and safety index were combined in order to form a comprehensive indicator for LOS.…”

Section: Crosswalk Facilitymentioning

confidence: 99%

See 1 more Smart Citation

Pedestrian flow characteristics and level of service on dissimilar facilities: A critical review

2018

View full text Add to dashboard Cite

Present paper reviewed the past studies on pedestrian flow characteristics (such as speed, flow, density, space, free-flow speed and jam density) and development of Pedestrian Level of Service (PLOS) for various pedestrian facilities (i.e., sidewalk, walkway, crosswalk, grade separated, stairways and escalators. Fundamental relationships (between speed and density) were observed over different facilities and were found to be significantly different. The fundamental relationships for sidewalk facility predicted the range of free flow speeds to be 65 − 85 m/min and jam densities to be 3.5 − 5.3 ped/m 2 . The minimum and maximum pedestrian speeds over sidewalk facility in different countries observed were 52 m/min and 98 m/min respectively, with a mean speed of 79 m/min. The male pedestrians walked at 4 − 9 m/min higher speed in comparison to their female counterparts; while the older pedestrians walked at 15 − 20 m/min lower speed than the younger ones over the various types of crosswalk facilities. Similarly, speed-density relationships for ascending and descending stairways showed that the difference between the two directions varied between 4 − 12 m/min, and that the speed was significantly higher in case of descending direction. Moreover, the jam densities for stairways were also observed to be lower in case of descending direction, as the pedestrians generally maintain higher gap (than in ascending direction) with other pedestrians in front to avoid pushing and the risk of falling down. The flow characteristics were significantly influenced by the type of facility, width, age, gender and location of the study. Primarily factors such as physique (height), culture (dress), attractions (presence of hawkers located along sidewalks), friction (due to parked vehicles), purpose of walking trip and environmental conditions were the main reasons for pedestrians of countries such as Saudi Arabia, Iraq, Bangladesh, Indonesia and Sri-Lanka to walk significantly slower than the counterparts pedestrians in the USA, UK or Canada. The review conducted on the PLOS mainly looked into the type of survey conducted (qualitative vs. quantitative), LOS parameters and the various software/models used in development of LOS. Researchers from the USA and Japan preferably used both qualitative and quantitative approaches in defining LOS over sidewalks; while in India, China and Malaysia qualitative method was highly preferred. Pedestrian volume, safety, surface, obstruction and width were observed as essential parameters for qualitative survey while density, flow rate, pedestrian speed and width were used in quantitative survey for sidewalks. In developing the PLOS over sidewalk facility; Conjoint analysis, Landis method, HCM method, affinity propagation cluster algorithm and Gainesville method were preferred by various researchers. Studies conducted over crosswalk facility measured space, flow rate, vehicle volume and delay as the most significant factors in developing LOS based on quantitative technique; while vehicle speed, ...

show abstract

Section: Crosswalk Facilitymentioning

confidence: 99%

Section: Crosswalk Facilitymentioning

confidence: 99%

Pedestrian flow characteristics and level of service on dissimilar facilities: A critical review

2018

View full text Add to dashboard Cite

show abstract

“…Some earlier methodologies [37] incorporated right turn through traffic and left turn for opposite traffic. Other variables include specific design of intersections and length of segments between intersections.…”

Section: Estimation Results Of Modelmentioning

confidence: 99%

“…Few studies that estimated intersection BLOS exist [30], [36], [37] and even fewer have considered a joint estimation of intersection and segment. Carter et al [30] developed an intersection safety index for North Carolina using the generalised linear models, while Landis et al [36] developed a Pearson Correlation and Factor Analysis-based methodology in estimating intersection LOS for the Florida Department of Transportation (FDoT).…”

Section: Intersection Bicycle Level Of Service (Intblos)mentioning

confidence: 99%

A Statistical Approach to the Estimation of Bicycle Level of Service Models for the Cicloruta in Bogota, Colombia

Okon

Brussel²,

Bosch³

et al. 2017

WIT Transactions on the Built Environment

View full text Add to dashboard Cite

Understanding the perception of level of service (LOS) of cyclists can be useful in developing a planning strategy for promoting intra-city bicycle commuting. In Bogota, the enormous resource investment in the Cicloruta system requires a regular infrastructure audit to ascertain its level of performance. Videos of 16 segments and 8 intersections were carefully collected and showed to participants who rated their level of satisfaction using a 6-point scale (A-F -'highly satisfied' to 'highly dissatisfied'), equivalent to 1360 segments and 680 intersections (2040 total ratings). The perception data was augmented with geometrical, physical and operational characteristics of traffic in the area. Most participants fall within ages of 18-35 in both male (88.9%) and female (77.4%) while bicycle ridership also revealed more riders in male (75.9%) than in female (58.1%). The study showed that 69.4% of participants ride bicycles in the city while 30.6% do not. Ordered probability models were used to estimate random parameters of cyclists LOS perception to account for unobserved heterogeneity for all respondents. Bicycle level of service (BLOS) was strongly influenced by side path separation (β=0.605, p<0.05); vehicle speed (β=0.717, p<0.05); motorised traffic volume (β=-0.381, p<0.05); and conflicts with pedestrians (β=1.173, p<0.05). Furthermore, other factors were also found to have high probabilities to influence LOS including bicycle lane width, wide outside lane, pavement conditions, trees and benches, daylight, gender and the experience of the cyclist. A model for intersection LOS was estimated, the results of which results reveal that the volume of cyclists (β=1.116, p<0.05), conflicts with pedestrians/other cyclists (β= 1.048, p<0.05) and total intersection legs (β=-0.365, p<0.05) are factors with a high influence on cyclist's LOS. The variety of factors affecting bicyclists reveal the nature and character of urban transportation in Bogota and suggest a range of important recommendations such as education and public enlightenment of cyclists and motorists, in further planning and management of the Cicloruta. Keywords: bicyclist, segment bicycle level of service, intersection bicycle level of service, ordered probit models, Cicloruta.

show abstract

“…The aim of the author was to optimize two objective functions at the same time: vehicle control delay and safety of vehicles and pedestrians at the intersections. Other researches that treat the traffic control problems from the aspect of traffic safety can be found in the following papers ( [5,14,22,24]).…”

Section: Introductionmentioning

confidence: 99%

Multi-Criteria Optimization of Single Intersection Under Over-Saturated Conditions

Jovanović¹,

Teodorović²

2019

MVM

View full text Add to dashboard Cite

Intersections are junctions where at least two roads or streets meet or cross. Consequently, they represent the most critical spots in the city traffic network, in terms of traffic safety. When determining the Level of Service at signalized intersections, the Highway Capacity Manual (HCM) does not take into account the traffic safety factors. In order to overcome this shortcoming, we propose in this paper the multi-criteria approach to the single intersection traffic control problem. The first objective function to be minimized is the average control delay experienced by all vehicles that arrive at the intersection. The second objective function to be minimized is the traffic safety risk index on intersection. These two criteria are in conflict, and the task is to find a good compromise between them. The analysed problem is solved by the combination of dynamic programming, and compromise programming. The proposed approach was tested in the case of the intersection that is controlled with two phases, under over-saturated traffic flows.

show abstract

Signalized Intersection Level of Service Incorporating Safety Risk

Cited by 42 publications

References 14 publications

Pedestrian flow characteristics and level of service on dissimilar facilities: A critical review

Pedestrian flow characteristics and level of service on dissimilar facilities: A critical review

A Statistical Approach to the Estimation of Bicycle Level of Service Models for the Cicloruta in Bogota, Colombia

Multi-Criteria Optimization of Single Intersection Under Over-Saturated Conditions

Contact Info

Product

Resources

About