Horizontal curves are a contributing factor for numerous deaths on roadways. The curve characteristics dictate the severity of the curve and require the driver to be more attentive while driving. To address this issue, advisory speeds are posted on horizontal curves to warn drivers to slow down for their safety. There are six main procedures to assign advisory speeds. This paper focuses on two of these methods, finds a connection between the two, and develops an Android Application that can be used to determine an advisory speed for a curve. In this work, a brief summary of the six existing methods for advisory speed assignment are discussed. Pros and cons are included for each for comparison purposes. Next, two of these methods are highlighted by applying them in the field. Data is collected and a relationship between them is determined. Using this relationship, an Android Application is created and the various details of the design process are described. This Application, called CurveAdvisor, allows the user to assign the appropriate advisory speed on a desired horizontal curve. An analysis is then conducted to test the effectiveness of CurveAdvisor. Results indicate that CurveAdvisor is successful in many cases. Finally, contributions and suggestions for future work are included. / Master of Science

One of the significant weaknesses of the design speed concept is that it uses the design speed of the most restrictive geometric element as the design speed of the entire road. This leads to potential inconsistencies among successive sections of a road. Previous studies documented that a uniform design speed does not guarantee consistency on rural two-lane facilities. It is therefore reasonable to assume that similar inconsistencies could be found on rural four-lane non-freeway highways. The operating speed-based method is popularly used in other countries for examining design consistency. Numerous studies have been completed on rural two-lane highways for predicting operating speeds. However, little is known for rural four-lane non-freeway highways. This study aims to develop operating speed prediction models for horizontal curves on rural four-lane non-freeway highways using 74 horizontal curves. The data analysis showed that the operating speeds in each direction of travel had no statistical differences. However, the operating speeds on inside and outside lanes were significantly different. On each of the two lanes, the operating speeds at the beginning, middle, and ending points of the curve were statistically the same. The relationships between operating speed and design speed for inside and outside lanes were different. For the inside lane, the operating speed was statistically equal to the design speed. By contrary, for the outside lane, the operating speed was significantly lower than the design speed. However, the relationships between operating speed and posted speed limit for both inside and outside lanes were similar. It was found that the operating speed was higher than the posted speed limit. Two models were developed for predicting operating speed, since the operating speeds on inside and outside lanes were different. For the inside lane, the significant factors are: shoulder type, median type, pavement type, approaching section grade, and curve length. For the outside lane, the factors included shoulder type, median type, approaching section grade, curve length, curve radius and presence of approaching curve. These factors indicate that the curve itself does mainly influence the drivers speed choice.

A potential factor for curve accidents are anticipatory skills. Horizontal curves have been recognized as a significant safety issue for many years. This study investigates the impact and effectiveness of three curve based perceptual speed calming countermeasures (advanced curve warning signs, chevron sign, and heads-up display(HUD) sign) on drivers’ hazard anticipation and mitigation behavior across both left and right-winding curves, and sharp (radius 200m) and flat (radius 500m) curves. Experimental results show that the speed and lateral control in the horizontal curves differed with respect to curve radii, direction, and the type of countermeasure presented. These differences in behavior are probably due to curve-related disparities, the type of perceptual countermeasure, and the presence of hazard at the apex of the curve. HUD is found to be effective at not only reducing the drivers’ speed in the curve, but also improve the latent hazard anticipation ability of the driver at the apex of the curve. Flat and sharp curves with indications of a safety problem were virtually developed in the simulator as representative as possible without upsetting the simulator’s fidelity. 48 participants were recruited for this study between the age range of 18 and 34, and driving experience range was from 0.25 to 17.75 years.

The subject of my thesis is a variant I/57 in the section Semetín-Bystřička. The proposed route of communication, was part of an existing communications maintained for its full utilization. Were drawn four proposed variants of the solution, 3 variants are trying their best to use existing communication Jablůnka the village, one suggested option B that leads outside the existing road.

These days most of the research related to autonomous vehicle technology focuses on vehicle technology itself and lesser on road infrastructure, including geometric design. This research project aims to lower the deficiency of research works required to make the optimized geometric road design for autonomous vehicle sustainable. In geometric design, significant concerns are designing the road geometrics such as lane width, the radius of horizontal curves, sag vertical curves and crest vertical curves, extra widening, setback distance, and intersection, making the road safer for the vehicles to travel comfortably.Road geometrics is widely designed using the stopping sight distance model, which provides sufficient time to avoid accidents and is efficient. Here in the research work, the stopping sight design model is used for autonomous vehicle technology. At first, the art of autonomous vehicle technology is studied, and a significant difference between autonomous vehicle technology and human-driven vehicle to apply stopping sight distance model is figured out. A literature study is also done for the geometric design of the road for the vehicle with the human driver and autonomous vehicle. The AASHTO model derived for the human-driven vehicle is used and modified for the autonomous vehicle, which gives the optimized geometric design for the autonomous vehicle. The Optimized geometric design parameter is designed individually in AutoCAD Civil 3D. Two road designs follow this in a random rural topography consisting of a normal road design for the vehicle with the human driver and a fully autonomous vehicle. Finally, the sustainability of optimized geometric design compared to road design for the human-driven vehicle is checked in terms of earthwork, pavement surface areas, and pavement materials volume. The result shows that the optimization of a geometric road design for autonomous vehicles is sustainable and extensive research is required.

The aim of the diploma thesis is the reconstruction of Milevsko railway station. The platforms with access persons with reduced mobility are designed in this station. The rail substructure and station drainage system design was necessary to do within the reconstruction. New assembly of a switches and crossing is the part of reconstruction design as well.

This graduation thesis deals about researching study of by-pass road of city Hustopeče, district of Břeclav, Southmoravian region. This city passes main road number 425, which should be connected with the by-pass road. The by-pass road will be designed as road of category S9,5/70 and will be situated west of the city. Terrain is undulated and composed of agricultural parcels. The main purpose of this by-pass road is significant burden of region traffic.

Aim of this Master´s thesis is the road adjustment and design of new grade separated junction highway R43 and road I/43,of Černá Hora – Svitávka and to design optimal distribution of transport hubs including the design II/150 and III/37429, which should be connected with existing roads.The adjustment of the routes will be designed in the necessary extent with the optimal distribution of transport hubs regarding the best transport and economical solution and with minimal impact on the enviroment.

This diploma work deals with researching study of transport junction of main road I/38 and major road II/523 and than link-up of the proposed Outer ring road (VMO) and Southeastern by-pass (JVO) routes of region capital Jihlava, district of Jihlava, Vysočina region. Road structure will solve designed staged link-up of aboved mentioned roads according to their construction schedule. The design takes into account current roads and completed stages, with respect to minimum costs. Road structure is situated on Czech-Moravian Highlands. Its terrain is hilly, pondy and composed of agricultural parcels. The main purpose of this design is steady link-up of all considered traffic flows in the given locality.

The aim of the diploma thesis is the reconstruction of Prostějov hl. n. railway station. The platforms with access persons with reduced mobility are designed in this station. The rail substructure and station drainage system design was necessary to do within the reconstruction. New assembly of a switches and crossing is the part of reconstruction design as well.