The Accuracy of Digital Models for Road Design - Geoinformatics for Intelligent Transportation - page 234

capacity, fuel consumption and emissions will be of high quality. Only on the basis
of high quality three-dimensional data it is possible to determine the horizontal and
vertical axis of communication and to optimize the location of the axis, and con-
sider operational, economic and environmental performance.

Keywords EIA DTM accuracy Methods of DTM measuring

1 Introduction

Construction of roads is a very complicated process financially and

organizationally. Preparation, realization and the construction itself will change the
neighbouring terrain and the environment related to the construction for a long time.
The basic source materials for road preparation, planning and construction are the
surveying data obtained by various surveying methods. The geodetic, photogram-
metric and laser scanning methods belong to them. Outputs of these methods
provide the basic information for all stages of the road construction, from study of
the road run up to the construction implementation.

— spatially,

2 Data and Surveying Methods Used During the Road
Planning

Data sources must be provided for preparation stage as well as the implementation
itself. Majority of the data should be in 3D form. The topicality, accuracy, cor-
rectness and suitability of the sources for the planning and implementation itself
must be considered. Within preparation of the source materials, data and maps, it is
necessary to concentrate on early obtained documents made by state administration
bodies, which should be veri ed for topicality and accuracy. If they do not comply

with the required accuracy or topicality, new data must be obtained.
When determining the area for motorways and first class roads in the Czech

Republic, the 1:200,000 regional schematic road maps are used. Another map
source is usually the Czech Republic (CR) 1:50,000 road map depicting the
motorways, roads, grade separations, nodal points of the localization system of the
road databank, bridges, underpasses, railway-crossings, tunnels, ferries, curves,
risings, passes, etc. Also cadastral maps, which contain points of the point field,

planimetry, all real estates, parcel indexes and relevant cadastral territory, are used
for designing works. From the Partial Territorial Decision level, the designer
requires current cadastral maps in vector form, i.e. the digital cadastral map or
digitized cadastral maps.
Geodetic data forms the basis of the special-purpose materials that practically
enables to incorporate the construction into the area of interest. The detailed point

field serves to that purpose. In the CR, the digital terrain model is used for the study