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Proportion-Based Format System for Freeway and Expressway Guide Signs
Abstract
The Manual on Uniform Traffic Control Devices has grown much more complex since 1961, the year that a section on signs for freeways and expressways was added to the manual. Yet that growth has been reflected primarily in the addition of more regulatory signs and a great deal of qualifying language. The standards for sign legibility and layout have changed little; however, the complexity of the roadway environments and the demand placed on the system has changed substantially. This paper builds upon previous work by the writers, which proposed similar formatting for conventional road guide signing. The intent of the system proposed in this new work is to improve the consistency and uniform readability of freeway and expressway guide signs based on defined proportions for key dimensions including: border, figure and field relationship, and line space. This design scheme rests on a foundation of proportional relationships made uniform for all common applications based on the common dimension ("X") of the height of the primary legend's lead capital letter.
... Previous research on expressway guide signs has mostly focused on how physical parameters, such as sign materials, structure, and guide information presentation including format, font, colour, and volume influence the driver's recognition and attention [3][4][5][6][7]. Particularly, the excessive amount of information on guide signs influences drivers' reaction time and increase the driver's visual load and mental stress, so the screening and stratification of guide sign information were also widely explored [8][9][10]. ...
The reasonable placement of the advance guide signs (AGSs) is important in improving driving efficiency and safety when exiting an expressway. By analysing the lane-changing process when approaching an exit on new two-way eight-lane expressways, we modified the tradi-tional AGS model lane-change distance formula. To this end, a field experiment was designed to explore the lane-change traversal time at the free flow condition (LOS 1). Considering the limitations of the experimental equip-ment, lane change distance at the worst levels of service was explored using VISSIM simulation. The results show that the eight-lane changing distance based on modified theoretical calculations, revealed a minor difference with VISSIM simulation in free flow condition. Further-more, placement distance at the worst levels of service are discussed. Then placement distance of all-level AGSs is recommended to be 3 km, 2 km, 1.2 km, and 0.8 km, considering the driver's short-term memory attenuation calculation formula. Determining the two-way eight-lane AGS placement distance from the perspective of LOS can provide a basis on which to supplement the existing stan-dards and references for the AGS placement distance af-ter the expressway expansion in China.
... Kim et al. [14] determined the letter size of traffic signs and the amount of layout information by analyzing factors such as the minimum vision sensitivity and reaction time required by drivers. Meeker et al. [15] studied the relationship between the character design of the sign layout and the size of the reference letter based on the highway complexity and information requirements and determined the information volume and combination arrangement of the layout design. ...
For the lack of quantitative basis of traffic sign combination information, this paper established a model of information quantity of urban road traffic signs by analyzing the driver’s information processing and the visual recognition of traffic signs combined with theories of informatics. It used various analytical methods to build a model of the relationship between the traffic sign information quantity (TSIQ) and the driver’s visual recognition. Based on factors, the relationship between the TSIQ and the driver’s visual recognition was studied and analyzed to provide a reference for the design of urban traffic sign layout information. The results show that the TSIQ can explain 61% of the driver’s recognition time (DRT). The more information the road traffic sign conveys, the longer DRT will be. The TSIQ’s threshold is 642 bits, and exceeding this value will cause information overload. Different influence factors have a certain impact on drivers’ visual recognition distance (VRD). The male VRD is shorter than the female. The VRD of the young driver is larger than the old driver. The VRD of a novice driver is longer than an experienced driver, while the visual recognition sign of an experienced driver is shorter.
... Through experiments, some scholars [17,18] proposed the satisfying number of guide signs in each guide sign panel to be accepted effectively. In terms of human ergonomics, some researchers [19][20][21][22] proposed the appropriate colours and patterns of guide signs. (ii) Intelligent placing of guide signs. ...
Guiding accessibility is a principal function of guide sign, which indicates whether the guide signs can guide people to their destinations successfully or not. The authors build an effective model to optimise the guiding accessibility of guide signs with a minimum economic cost. The authors’ work can benefit guide sign setting, and improve the efficiency of the traffic system. Firstly, the authors introduced the representation of the road network, then the accessibility and integrated optimisation of guiding paths are defined. Based on this, an integrated optimisation model is proposed with the optimisation of the guiding path length and the number of guide signs. Then combining with the genetic algorithm, the algorithm is designed to solve the mixed integer linear programming problem. Lastly, Guangzhou Higher Education Center is chosen as the test area. The integrated optimisation of the multiple guiding paths with the destination of Sun Yat‐sen University is realised using the proposed model. The experiment results show that the proposed model can realise the integrated optimisation of an unsuccessful guiding path with the minimum economic cost.
Advance guide signs for exit ramps along urban expressways are increasingly critical, enhancing safety and mobility by improving the flow of vehicles exiting urban expressways. However, research has devoted scant attention to advance guide signs for exit ramps. This study aimed to identify and propose optimal design alternatives for exit ramp advance guide signs for different types of exit spacing. This study conducted a driving simulation experiment consisting of five design alternatives of advance guide signs and two exit ramp spacing variation. Eight indicators were measured. The repeated-measure analysis of variances (ANOVA) and the Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS) were performed for the influence analysis and efficiency evaluation of different schemes. Influence analysis results showed better design alternatives in five schemes of advance guide signs, enabling drivers to more easily locate destination exits and change lanes fewer times, in addition to reducing drivers' need to decelerate, and improving traffic flow in the key influence range of destination exit ramps. The percentage of drivers successfully locating the destination exits also increased with optimal design alternatives of advance guide signs. When the exit ramp spacing tightened, on the other hand, drivers had to make more lane changes and accelerate and decelerate more frequently in the key influence range. As a result, a lower percentage of drivers successfully located destination exits. Efficiency evaluation results were also obtained. In tight spacing, three advance guide signs are recommended to be placed at 1 km, 0.5 km and 0 km prior to the beginning of the tapered deceleration lane. If conditions are limited, at least two advance guide signs should be used. With greater spacing, four advance guide signs are recommended, located at 2 km, 1 km, 0.5 km, and 0 km prior to the beginning of the tapered deceleration lane. If road conditions are limited, three advance guide signs should be used.
The research objective was to improve highway guide sign legibility by replacing the 40-year-old guide sign font with a new font called Clearview. It was believed that the current guide sign font's thick stroke design, made with high-brightness materials and displayed to older vehicle operators, exhibited a phenomenon known as irradiation or halation. Irradiation becomes a problem if a stroke is so bright that it visually bleeds into the character's open spaces, creating a blobbing effect that reduces legibility. The Clearview font's wider open spaces allow irradiation without decreasing the distance at which the alphabet is legible. Results are presented of two daytime and two nighttime controlled field experiments that exposed 48 older drivers to high-brightness guide signs displaying either the current or the Clearview font. The Clearview font allowed nighttime recognition distances 16 percent greater than those allowed by the Standard Highway Series E(M) font, without increasing overall sign dimensions.
The Manual on Uniform Traffic Control Devices and the Standard Highway Signs Book have been developed around the use of the FHWA Standard Alphabets in an all-uppercase format for use on conventional road guide signs. These publications include a complex series of dimensions and tables based on specific legend sizes for various standard signs; however, the standards do not include guidance for the myriad different layouts that are developed to address unique local conditions. The mathematical relationship of the legend to the border, border size, and line spacing and the mathematical relationship of the graphics to the panel are not based on any standard criteria; as a result, sign layouts are not consistent for signs of similar types. In this paper, a recommendation is made to simplify the formatting of conventional road guide signs. Although these signs are used for many purposes, a similarity in their general design principles provides a basis for a common system of sign layout that relates all of the various dimensions (e.g., border width, word and graphic spacing, and line spacing) to a single common element, the height of the letters used on the sign (for mixed-cased applications, the height of the initial capital letter). To accommodate the use of mixed-case words, a series of proportion-based grid formats has been developed. This series of layout grids is based on the value X, where X is the size of the initial capital letter of the primary legend. The proposed formatting is called the proportional grid system.
The Manual on Uniform Traffic Control Devices and the Standard Highway Signs Book have been developed around the use of the FHWA Standard Alphabets in an all-uppercase format for use on conventional road guide signs. These publications include a complex series of dimensions and tables based on specific legend sizes for various standard signs; however, the standards do not include guidance for the myriad different layouts that are developed to address unique local conditions. The mathematical relationship of the legend to the border, border size, and line spacing and the mathematical relationship of the graphics to the panel are not based on any standard criteria; as a result, sign layouts are not consistent for signs of similar types. In this paper, a recommendation is made to simplify the formatting of conventional road guide signs. Although these signs are used for many purposes, a similarity in their general design principles provides a basis for a common system of sign layout that relates all of the various dimensions (e.g., border width, word and graphic spacing, and line spacing) to a single common element, the height of the letters used on the sign (for mixed-cased applications, the height of the initial capital letter). To accommodate the use of mixed-case words, a series of proportion-based grid formats has been developed. This series of layout grids is based on the value X, where X is the size of the initial capital letter of the primary legend. The proposed formatting is called the proportional grid system.
Standard highway signs book
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Manual on uniform traffic control devices
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