Proposal to build only 80 km/h highways in difficult mountainous terrain

The Ministry of Transport is currently seeking comments on the draft Circular promulgating National Technical Regulations on highway design.

Accordingly, based on the design speed, highways are divided into 3 levels. Level 80 has a design speed of 80 km/h, level 100 has a design speed of 100 km/h, level 120 has a design speed of 120 km/h. Special design level, design speed over 120 km/h, is researched and designed separately.

In which, level 80 is the minimum design level that should only be applied to areas with difficult terrain such as mountainous areas, high hills or in cases of investment divergence.

The selection of highway level must be based on terrain conditions, established road network planning, approved by competent state authorities, on the basis of research, analysis and full assessment of economic - technical - social factors.

On a highway there may be sections with different grades applied, but uniformity must be ensured along the length of each section.

For particularly difficult locations, the design speed can be reduced to reduce investment costs, but in all cases it must not be less than 60 km/h, and at the same time, it is necessary to gradually change the speed and arrange appropriate signals. Sections with different speeds must be at least 2 km long and the calculated speed of two consecutive sections must not differ by more than 20 km/h.

The draft circular also stipulates that the road surface (traveling area) in each direction on a complete highway must have at least 2 lanes/direction and must ensure sufficient capacity for the calculated traffic volume.

Bridges on highways must have the same cross-sectional elements as the adjacent road, and the bridge width must not be narrower than the adjacent road width.

Regarding tunnel projects, the draft circular stipulates that tunnels with a length of less than 1,000m do not have to arrange emergency stops.

Tunnels with a length of 1,000m or more must have emergency stops at each section at least 30m long and a maximum of 500m apart. The width of the stopping lane depends on each highway level.

Event - Proposal to build only 80 km/h highways in difficult mountainous terrain — According to the draft Circular, level 60 has a design speed of 60 km/h and is only designed for construction in particularly difficult locations when necessary to reduce investment costs.

Also according to the draft Circular, along the highway, service facilities must be arranged and built for all road users. Service facilities are divided into 4 types. Type 1 has a minimum station area of 10,000 m2, and a parking area of at least 5,000 m2. Type 2 has a minimum station area of 5,000 m2, and a parking area of at least 2,500 m2. Type 3 has a minimum station area of 3,000 m2, and a parking area of at least 1,500 m2. Type 4 has a minimum station area of 1,000 m2, and a parking area of at least 500 m2.

Regarding distance, every 15 km to 25 km, there is a parking lot along the route outside the road surface where road users can stop to rest, enjoy the natural scenery and maintain their vehicles; the location can be chosen from a few dozen meters to hundreds of meters away from the road.

Every 50 to 60 km, arrange a regular technical service station (capable of supplying gasoline, oil, charging electricity, minor repairs and stopping vehicles, with rest houses, toilets, and restaurants) of type 2 scale.

Every 120 km to 200 km, arrange a large service station (capable of repairing vehicles, supplying gasoline, oil, charging electricity, and also being able to welcome travelers with restaurants, hotels, tourist information offices, transfer instructions...), considering the suitability for the majority of customers and also having a long-term parking space of type 1 scale.

In addition, on highways, there must be parking lots along the route arranged in places with beautiful scenery with different scales. For short-term parking, from 1 to 3 cars can stop, a rest tent with a tourist map can be arranged... with a scale of type 4. For long-term parking, many cars must stop and there can be refreshment stalls, telephone booths, gas stations,... with a scale of type 3.

Service facilities must be located at convenient entrances and exits, not obstructing the view of slopes or curves and far from intersections; entrances and exits must have a speed limit of less than 40 km/h .

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