Inventory and Analysis
Inventory and Analysis
This domain tests how you collect site facts and turn them into design decisions. Questions cover base maps, field verification, data sources, constraints and opportunities, suitability analysis, and graphic analysis methods.
Core rules
- Inventory records existing conditions: boundaries, contours, utilities, vegetation, structures, easements, zoning, soils, hydrology, views, and circulation. Analysis interprets those facts for a program.
- Verify source, date, scale, and datum. A recent aerial may not show a new easement or culvert; field checks catch what maps miss.
- Common analysis maps include slope, drainage patterns, solar orientation, viewshed, noise, access, and soil limitations. Overlay or weighted scoring can compare alternatives.
- Separate fact from judgment. "Twelve percent slope" is inventory; "poor for an accessible path" is analysis.
Worked example
A proposed accessible path crosses a slope with a 12-foot elevation change over 100 feet. The gradient is 12 feet divided by 100 feet, or 12 percent. For an accessible route, that exceeds the 1:20 maximum running slope of 5 percent without a ramp and landings. The reasoning: first compute the actual gradient, then compare it with the applicable accessibility criterion, then adjust the alignment, add switchbacks, or design a compliant ramp. Do not assume a gentle-looking contour pattern is compliant.
Traps
- Mixing inventory with analysis in written responses.
- Using an outdated aerial or GIS layer without checking its date and scale.
- Ignoring easements, drainage crossings, or utility conflicts until design.
- Treating a constraints map as a final suitability decision without field verification.
Key ideas
A defensible analysis shows the data source, the interpretation method, and the design consequence.