Highway Data
One of the first steps in using IHSDM is to compile data describing the highway to be evaluated. The exact data requirements depend on which safety module(s) will be used. In general, data requirements may include highway segment geometry (horizontal alignment, vertical alignment, and cross section), roadside geometry, intersection geometry, traffic volume data, and crash data. To illustrate IHSDM data, the full distribution includes sample highway files.
Much of the highway segment geometry data required by IHSDM is available in the civil design software packages used in highway geometric design. With the objective of minimizing the effort required by the user to export data from these packages and import into IHSDM, the following mechanisms for data exchange are available:
- LandXML 1.0 data exported by civil design software packages can be imported into IHSDM.
- GEOPAK data can be extracted from GEOPAK 2001, 2000 and 98 using a GEOPAK-to-IHSDM Data Extractor in a format that can be imported into IHSDM. The data extractor is distributed with IHSDM. Newer versions of GEOPAK can export the alignment data into LandXML format that can be imported into IHSDM.
- CAiCE data can be extracted using CAiCE's IHSDM Toolbox in LandXML format, which can be imported into IHSDM. CAiCE distributes the IHSDM Toolbox with their Visual Roads civil engineering software. (Note: CAiCE's IHSDM Toolbox provides access to the IHSDM 2004 Public Release, including related documentation. Users of the 2015 Public Release should access the IHSDM software and documentation directly from this web site.)
Sample Highway Files
The full distribution of IHSDM includes a highways folder that contains sample highway files. These files contain geometry data needed by IHSDM and may be used as a starting point for IHSDM testing and evaluation.
The following sample files are provided in the highways folder of the IHSDM 2015 - HSM Predictive Method Release Update:
- ihsdm.network.Example Freeway.xml - An "Example Freeway" highway network that contains a 6-lane freeway segment with 2 crossroads and 2 interchanges, including C-D roads, ramps and ramp terminals.
- ihsdm.siteset.Example Freeway SiteSet.xml - An "Example Freeway" Site Set that contains a 6-lane freeway segment with 2 crossroads and 2 interchanges, including C-D roads, ramps and ramp terminals. This is the "Site-Based" version of the "Station-Based" Example Freeway file (ihsdm.network.Example Freeway.xml).
- ihsdm.network.example.xml - a highway data file for “IHSDM Pike,” an existing 2.7 mile highway section. The file includes data for an intersecting highway (“Route 1”) and the intersection of IHSDM Pike and Route 1. The Workflow Wizard gives an option to create a sample project; this highway data file is loaded when the sample project is created. This highway is imported in Tutorial Exercise 4.4.
- ihsdm.network.ihsdm pike.xml - a highway data file for “IHSDM Pike,” an existing 2.7 mile highway section. The file includes data for an intersecting highway (“Route 1”) and the intersection of IHSDM Pike and Route 1. This file is basically equivalent to the ihsdm.network.example.xml file. This highway is imported in Tutorial Exercise 2.11, and used in Tutorial Exercises 3.1, 4.1, 5.1, 6.1, 7.1 and 8.1.
- ihsdm.network.ihsdm pike_altA.xml - a highway data file for “IHSDM Pike - Alternative A,” which is "IHSDM Pike" with widened travel lanes and added shoulders. This highway is used in Tutorial Exercises 3.2 and 4.2.
- ihsdm.network.ihsdm pike_altB.xml - a highway data file for “IHSDM Pike - Alternative B,” which includes the same improvements as "IHSDM Pike - Alternative A" (widened travel lanes and added shoulders), plus the additional improvement of replacing a sharp compound curve with a single, flatter curve. This highway is used in Tutorial Exercises 3.3, 4.3 and 5.2.
- ihsdm.network.ihsdm pike_altC.xml - a highway data file for “IHSDM Pike - Alternative C,” which is "IHSDM Pike" with a climbing lane added for a 0.5 mile section, and improvements to the intersection of IHSDM Pike and Route 1 (e.g., reduced skew). This highway is used in Tutorial Exercises 6.2 and 7.2.
- ihsdm.network.ihsdm pike_altD.xml - a highway data file for “IHSDM Pike - Alternative D,” which includes the "IHSDM Pike - Alternative A" improvements (widened travel lanes and added shoulders), plus several horizontal curve radii are increased to meet 2011 AASHTO policy. This highway is used in Tutorial Exercise 8.2.
- ihsdm.network.IHSDM Pike - Urban Arterial.xml - an urban arterial version of IHSDM Pike, used in Tutorial Lesson 4 (Crash Prediction Module), Exercise 4.5
- ihsdm.network.irm_example.xml - provides data for six highway sections and four intersections, including four-leg intersections with all-way STOP-control, yield-control and no control, and a five-leg intersection with yield-control.
- Two-lane Rural Highway.xml – a 20,000 ft long two-lane rural highway, with data for four intersecting highways and their intersections
- Two-lane Rural Highway Alt1.xml – an alternative design to “Two-lane Rural Highway.xml” (TWLTL and climbing lanes added, and shoulder, driveway density and roadside hazard rating modified)
- Multilane Rural Highway.xml – a 20,000 ft long multilane rural highway, with data for four intersecting highways and their intersections
- Multilane Rural Highway Alt1.xml - an alternative design to “Multilane Rural Highway.xml” (thru lane width and shoulders modified)
- Multilane Rural Siteset.xml – a sample Site Set, containing data for Four-Lane Undivided Segments, Four-Lane Divided Segments, Three-Legged Minor-Road Stop Control Intersections, Four-Legged Minor-Road Stop Control Intersections, and Four-Legged Signalized Intersections. This Site Set is used in Tutorial Lesson 4 (Crash Prediction Module), Exercise 4.7, Section III.
- Urban 6F – HSM Sample Problem 5.xml – a 20,000 ft long urban 6-lane freeway (Urban 6F), as described in draft HSM Chapter 18 Sample Problem 5.
- Urban Arterial.xml - a 20,000 ft long urban arterial, with data for four intersecting highways and their intersections
- Urban Arterial Alt1.xml - an alternative design to “Urban Arterial.xml” (thru lane width, shoulder, lighting, automated speed enforcement modified)
- DCM Lower-speed Example.xml - a 10,000 ft long, curvilinear (6 horizontal curves) rural two-lane highway, with a posted speed of 40 mph
- Highway 67.xml - a rural two-lane highway, used in Tutorial Lesson 2 (Data Input), Exercise 2.2.
LandXML Data
LandXML is an industry-developed standard schema for the exchange of data created during land planning, surveying, and civil engineering design processes by different applications software. IHSDM supports the LandXML Version 1.0 data exchange format.
IHSDM can import data exported by other commercial civil design packages in LandXML format. See http://www.landxml.org for a list of civil engineering design packages and other software applications that support LandXML.
GEOPAK Data
For use with GEOPAK 2001, 2000 and 98, the GEOPAK-to-IHSDM Data Extractor extracts from GEOPAK (*.GPK and *.INP files) a subset of the geometric data required to run IHSDM and converts the data to a format that can be imported into IHSDM. The geopak_to_ihsdm_api folder contains the API software (g2ihsdm.ma) and a set of sample files. For newer versions of GEOPAK export the alignment data into LandXML format and import it into IHSDM.
The following sample files are provided:
* example.txt - an IHSDM highway data file extracted using the GEOPAK-to-IHSDM Data Extractor from the GEOPAK jobprm.gpk and example.inp files. Some data elements that cannot be extracted from GEOPAK (e.g., average daily traffic) were added to the file manually using a text editor. * jobprm.gpk - a GEOPAK (*.GPK) file containing horizontal (chain) and vertical (profile) alignment data extracted by the GEOPAK-to-IHSDM Data Extractor. * example.inp - a GEOPAK auto shape input (*.INP) file containing the cross-slope data extracted by the GEOPAK-to-IHSDM Data Extractor. * example.dgn - a Microstation SE design file that illustrates the horizontal and vertical alignments.
The jobprm.gpk and example.inp files may be used to illustrate how the GEOPAK-to-IHSDM Data Extractor extracts data from GEOPAK and creates IHSDM highway data files (e.g., example.txt).
CAiCE Data
CAiCE Visual Roads civil engineering software includes an IHSDM Toolbox that can be used to export data from CAiCE Visual Roads in LandXML format. The data that are exported from Visual Roads include superelevation tables, horizontal and vertical alignments, and cross-sections. The data file exported by the CAiCE's IHSDM Toolbox can be imported to IHSDM using the LandXML import capability. (Note: CAiCE's IHSDM Toolbox provides access to the IHSDM 2004 Public Release, including related documentation. Users of the 2015 Public Release should access the IHSDM software and documentation directly from this web site.)