Purpose

The GeoStats group of the Newfoundland Statistics Agency, Department of Finance, Government of Newfoundland & Labrador, created the Newfoundland & Labrador Road Distance Database software to give users approximate road distances and travel times between places in Newfoundland & Labrador.

Assumptions

The needs of the varied target audience require a differentiation between absolute distances and travel time between two selected communities. Where two routes are possible the route via automobile travel takes precedence over a passenger ferry option. These two measures are considered ‘costs’ and the choice will vary by application.

Caveats

The database offers two solutions using two sets of criteria. The distances solution is the ‘shortest network path’ in absolute minimum distances given the existing road network. The ‘travel time’ is calculated as minimums but by using the cumulative times of traversing the road segments at the established rate of speed. (See Table 1.) Thus, there is no assurance that the least distance route is the same route used to determine the least travel time.

For example, the absolute minimum distance between Placentia and St. John’s is 126 kilometers via Colinet and Salmonier Line. The minimum travel time is via the more popular Whitbourne –TCH. This is a case where it takes a shorter time to travel a longer distance because of a faster rate of travel. These cases are relatively few.

The ferry system can affect assumptions made by end-users. Several ferry routes are restricted to pedestrian passengers. This becomes an issue in cases of travel between communities on the Burin Peninsula and communities on the Connaigre Peninsula (Harbour Breton area).

The passenger ferry service from Bay L’Argent and Pool’s Cove provides the shortest distance and time but the automobile option is considerably longer requiring travel to Grand Falls-Windsor and then south on the Bay’ D’Espoir Highway (Route 360). Travel between Labrador and the Island of Newfoundland is restricted to the Labrador Straits (Strait of Belle Isle). The seasonal ferry between Lewisporte and Happy Valley-Goose Bay is not considered a viable option for regular travel and solutions are not provided.

The Provincial Ferry Service should be consulted for seasonal, remote and island-community accessibility.

Procedure

The calculations were obtained from a modified street network file of the Province obtained from CompuSearch since bought by MapInfo. The network file was CompuStreets version 3.0, February 2000. The community features were developed in-house as a point feature coverage representing selected populated places.

These coverages were imported as a project file into ESRI’s ArcView (3.2). A supplemented extension module, Network Analyst, was used to actually calculate the ‘costs’ (distance and time) between the community points.

The database results were compiled into a Microsoft Access Database, which is used by the Newfoundland & Labrador Road Distance Database interface.

Error Sampling

The results were compared to the ‘Kilometer Guide’ published as an inset of the 1999 edition of the Official Highway Map. Minor discrepancies were anticipated between the two sources in the order of 10 kilometers. Most minor differences can be attributed to the representation of large areal or ribbon development features by a single representative point. The points used were chosen to be in or near the populated cores of settlements. Where possible a major road intersection was selected. 

Two areas were identified with large differences (> 30 km.), Fogo Island and the Southern Avalon. The Fogo issue may be explained by an apparent reliance on a discontinued ferry service between Carmanville and Fogo Island. For example, the Highway Map reports a distance of 13 kilometers while GIS calculations suggests 103 kilometers. These instances will occur between Fogo and communities to the southeast.

The Southern Avalon issue can be resolved by allowing the use of the Witless Bay Line to connect the Southern Shore to places west of St. John’s. For example, the Highway Map reports 121 kilometers between Ferryland and Holyrood while the calculations report 73 kilometers.

There are mid-range discrepancies (20-30 km.) with communities on the Cape Shore and those on the eastern Avalon. The suspicion is the completion of the North Harbour to Branch highway (Route 92).

Several recent major road projects will have significant impacts on local areas. The Conception Bay North by-pass, Goulds by-pass, Main Brook to St. Anthony airport and the Red Bay to Cartwright highway will affect existing and create new linkages.

2002-03-20.

Table 1: Assigned rates of speed by Roadway Class.

Road Class DEFINITION Travel Rate – km/hr
CS10 Restricted Access, Multi-Lane Highway: Ground 100
CS11 Restricted Access, Multi-Lane Highway: Bridge 100
CS12 Restricted Access, Multi-Lane Highway: Tunnel -
CS13 Restricted Access, Multi-Lane Highway: Proposed -
CS20 Provincial or Other Two-Lane Highway: Ground 80
CS21 Provincial or Other Two-Lane Highway: Bridge 60
CS22 Provincial or Other Two-Lane Highway: Tunnel -
CS23 Provincial or Other Two-Lane Highway: Proposed -
CS30 Secondary Road or Minor Highway: Ground 60
CS31 Secondary Road or Minor Highway: Bridge 60
CS32 Secondary Road or Minor Highway: Tunnel -
CS33 Secondary Road or Minor Highway: Proposed -
CS40 Local Road: Ground 50
CS41 Local Road: Bridge -
CS42 Local Road: Tunnel -
CS43 Local Road: Proposed -
CS90 Connected to a Local Road 50
CS91 Connected to a Secondary Road 50
CS92 Connected to a Highway 50
CS93 Ferry Route: Passenger 10
CS94 Ferry Route: Vehicular 10