Scenic Highway Designation

My Idea serial ID: 00413

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

conducted by madry, bochkay, hartman ©