Performance Measure that Indicates Geometry Sufficiency of State Highways. Volume 2: Clear Zones and Cross-Section Information Extraction.

摘要

Evaluation?method?employed?for?the?proposed?corridor?projects?by?Indiana?Department?of?Transportation?(INDOT)?consider?road?geometry?improvements?by?a?generalized?categorization.?A?new?method?which?considers?the?change?in?geometry?improvements?requires?additional?information?regarding?cross?section?elements.?Part?of?this?information?is?readily?available?but?some?information?like?the?embankment?slopes?and?obstructions?near?traveled?way?needs?tobe?acquired.?This?study?investigates?available?data?sources?and?methods?to?obtain?cross-section?and?clear?zone?information?in?a?feasible?way?for?this?purpose.?We?have?employed?color?infrared?(CIR)?orthophotos,?LiDAR?point?clouds,?digital?elevation?and?surface?models?for?the?extraction?of?the?paved?surface,?average?grade,?embankment?slopes,?and?obstructions?near?the?traveled?way?like?trees?and?man?made?structures.?We?propose?a?framework?which?first?performs?a?support?vector?machine?(SVM)?classification?of?the?paved?surface,?then?determines?the?medial?axis?and?reconstructs?the?paved?surface.?Once?the?paved?surface?is?obtained,?the?clear?zones?are?defined?and?the?features?within?the?clear?zones?are?extracted?by?the?classification?of?LiDAR?point?clouds.???SVM?classification?of?the?paved?surface?from?CIR?orthophotos?in?the?study?area?results?with?a?classification?accuracy?over?90%?which?suggests?the?suitability?of?high?resolution?CIR?images?for?the?classification?of?paved?surface?via?SVM.?A?total?of?21.3?miles?of?relevant?road?network?has?been?extracted.?This?corresponds?to?approximately?90%?of?the?actual?road?network?due?to?missing?parts?in?the?paved?surface?classification?results?and?parts?which?were?removed?during?cleaning,?simplification?and?generalization?process.?Branches?due?to?connecting?driveways,?adjacent?parking?lots,?etc.,?were?also?extracted?together?with?the?main?road?alignment?as?by-product.?This?information?may?also?be?utilized?if?found?necessary?with?further?effort?to?filter?out?irrelevant?pieces?that?do?not?correspond?to?any?actual?branches.?Based?on?the?extracted?centerline?and?classification?results,?we?have?estimated?the?paved?surface?as?observed?on?the?orthophotos.?Based?on?the?estimated?paved?surface?centerline?and?width,?we?have?generated?cross?section?lines?and?calculated?the?side?slopes.?We?have?extracted?the?buildings?and?trees?within?the?clear-zones?that?are?also?defined?based?on?the?reconstruction?of?the?paved?surface.?Among?86?objects?detected?as?buildings,?14%?were?false?positives?due?to?confusion?with?bridges?or?trees?which?present?planar?structure.