Stay off the highway

The allocation of resources in annual maintenance as well as land development control decisions and decisions about the level and kinds of access and roadside activities, should all be based on the class to which a road belongs. The country’s tourism drive makes it even more important that the roads are classified in a manner that is intuitive and easily understood by those unfamiliar with particular regions.

The current road hierarchy is defined in the Highways Act chapter 48:01.

Six categories of roads are defined. These are:

(a) Main roads,

(b) Special roads,

(c) Secondary roads,

(d) Local roads,

(e) Streets

(f) Development roads.

According to the Act “main road” means a highway that — (i) in the opinion of the Minister is of prime importance by reason of being a main channel of communication throughout Trinidad and Tobago; and

(ii) Is classified as such by Order made under the Act.

Secondary roads are considered of “secondary importance”. Special roads are main roads reserved for special classes of traffic and development roads are traces or trails constructed for agricultural or other development.

Streets are not defined by function, design or usage but are just “classified as such” and “local roads” are defined as none of the above.

CONFUSING DEFINITIONS

These definitions are clearly inadequate and cumbersome. One obvious flaw is that only main and development roads are really defined by their function. Also, there is nothing within the definitions which would indicate the level of jurisdiction or the level of design and construction of the roads. One result of this is that the Highways Division is responsible for some roads which mainly serve an access function, while conversely local government bodies are responsible for roads which serve mainly a movement function.

The main basis for classification should be whether the road is to be used primarily for movement of vehicles or for access to premises. A road hierarchy should be defined according to the functions that the roads will serve for safe, efficient and economic operations. Each class of road should clearly convey to the road user its role in the hierarchy by appearance and related operational standard. Also, each road should intersect only with roads in the same class or one immediately above or below it in the hierarchy, so that the change in operating conditions is gradual. What are the road classes?

Arterial roads are the main transport routes within the road hierarchy. Their function is for movement, and they operate under the following conditions: There is no direct access to premises; any development is set well back from the highway; all access to premises are provided via collector roads; the number of intersections is minimised; pedestrians are not permitted; and there is no stopping or parking on the carriageways. When there is no at-grade intersection these roads are known as freeways, and when there are limited at-grade intersections they are called expressways.

On some arterial roads there may be a relaxation of the direct access and pedestrian constraints, and in exceptional circumstances large individual developments may have direct access, and they are known as secondary or minor arterial roads, to differentiate them from primary or major arterial roads.

NO FREEWAYS - yET

There is no freeway as yet in Trinidad, the nearest example being the Solomon Hochoy Highway. The shortcoming of this arterial road is there are private individual accesses, and there are vendors and pedestrians on the highway. The Uriah Butler Highway cannot be considered a freeway because there are several at-grade intersections, and it is an expressway. It also suffers from similar problems as the Solomon Hochoy Highway. There are other examples of expressways such as the Churchill-Roosevelt Highway, the Audrey Jeffers Highway, etc. These may all be considered primary arterial roads.

Wrightson Road in Port-of-Spain and the San Fernando Bypass in San Fernando are current examples of secondary arterial roads.

Collector roads are immediately below arterial roads in the hierarchy. The needs of moving traffic still predominate but they also contribute to access requirements. They serve to feed traffic onto and off the arterial roads. They operate under the following conditions: direct access to premises should only be permitted where large traffic generators exist; motorists need to be aware of pedestrians as these roads will be within or close to residential areas; the road is only for local traffic and through-movements should be made awkward and inconvenient to discourage them; vehicle speeds should be kept low, so long straight roads should be avoided; parking may be allowed, but alternative off-road provision is preferable; and public transport stops may be located on the carriageway but should be near well-defined crossings. Examples of collector roads are Ariapita Avenue in Port-of-Spain, Coffee Street in San Fernando, and Ramsaran Street in Chaguanas.

Local roads are for access only. They function under the following conditions: Vehicle flows must be kept to a minimum; all unnecessary traffic should be eliminated; vehicle should be kept low by careful and deliberate inclusion of obstructions to create meandering alignments; roads should be kept short where possible; cul-de-sac and loop roads should be used wherever possible to deter through-traffic; intersections should be three-legged (where three roads meet) rather than four-legged and kept compact to aid pedestrian movement; and, parking and stopping within the street is permitted, although adequate provision should be provided within individual properties.

The Southern Main Road, Eastern Main Road, Diego Martin Main Road, Naparima-Mayaro Road, for instance, once functioned as secondary arterial roads. Intense uncontrolled urbanisation has adjusted their operation to a combination of all the categories of road classification.

(Continued next week)

e-mail: lfsystems@carib-link.net