Scenic Highway Designation

GOALS

Test GIS for use in identification of scenic byways:

determine requirements
interpret scenic characteristics as GIS data layers
develop models for identification
apply models to roads in distinct physiographic regions

Test GIS for use as a tool for evaluation of scenic byways:

compare ranking systems from visual analysis to data layers in GIS
develop and test evaluation models

APPROACH:

Review scenic byways report from New Jersey Department of Transportation
General literature review of scenic highway designation approaches
Collect available data layers
Conduct GIS analysis
Perform field evaluation of sites along route 29
Analyze results of field evaluations in terms of data available on a GIS
Refine model
Test model on 15 additional field sites along route 29
Refine model
Apply to roads in Hunterton County (rt. 12)
Refine model
Apply to roads in Cape May County
Analyze and evaluate results

Products and Results

Viewshed maps for Route 29

viewsheds generated by the GIS, based on topographic analysis
initial model used 2 km sightlines
illustrated with landcover and other GIS data

Scenic quality of sites was evaluated on Route 29

photo analysis of Route 29 sites was conducted
these sites were evaluated, ranging from excellent to poor
characteristics of data layers were analyzed for the viewshed for the Route 29 sites
simple model was developed to rank views from 15 additional sites

Rankings were tested via field visits

field rankings were compared to model predictions
the model was determined to be successful

Model was applied to Route 12 in Hunterton County

field tests show that maps were generally accurate
actual extent of the viewshed was greater than modeled extent
model was rerun to include areas within 5 km, rather than 2 km of highways

Model was applied to roads in Cape May

model predicted landcover classes accurately
desirability of views of land cover types varies among physiographic regions
maximum views had to be increased, 10 km is probably optimum
height of canopy must be adjusted for each physiographic region

Summary

This pilot study successfully illustrates current and potential applications of GIS to scenic byways identification within the time and funding limitations of this study. We also identified a number of limitations caused by lack of data availability, computer time requirements for analysis and technical constraints in the software.

Appropriate applications:

automatic identification of viewsheds
evaluation of viewsheds based on physiographic data
application of evaluation methods within regions

Potential applications:

evaluation of viewsheds based on cultural and political data
developement of regional criteria for scenic ranking (requires additional field testing of NJDOT surveys
first order scanning of highways, statewide for viewshed characteristics (requires extensive computer time)

Limits of current technology:

ranking views within the criteria set forth by the current NJDOT evaluation method. (A field evaluation technique could be developed that more effectively utilizes the type of information that can be included in GIS data layers.)
scalar differences between available GIS data and the characteristics typically used in viewshed analysis, limited dedicated GIS modules
tenuous coorelation between qualitative visual analysis and quantitative GIS data analysis

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Quicktime movie

A player for this Quicktime movies is called xanim and can be downloaded from here For more information contact Scott Madry or Rich Bochkay at The Grant F. Walton Center for Remote Sensing and Spatial Analysis.