Laminar traffic flows and Dynamic hard shoulder utilization

- Enhancing efficiency of existing road infrastructure

Two simple rules are applied on urban highways:

1. Vehicles can utilize hard shoulders but only at appropriately low speed. This ensures safe use of hard-shoulders.2. There is a growing minimum distance of 'sticking within the lane' towards the middle of the road. A sensible criteria is along these lines:- outermost lane: no restriction- 2nd lane from outside: at least 1 km or mile straight driving before switching to outer lane- 3rd lane from outside: at least 10 km or mile straight driving before switching to outer lane

Hard shoulder

1st effect: Traffic flows more smoothly when unnecessary lane changes are avoided

Hard shoulder

Lane changes disrupt traffic flow and reduce capacity

Transit traffic flows through, fewer lane changes increase traffic capacity

Hard shoulder

2nd effect: Transit flows are less affected by local congestions

Hard shoulder

Transit flows are hindered by each locally arising congestion

Transit traffic flows are much less affected by local congestions

It is also checked that drivers don’t try to skip the exit queue, holding up everyone else, but get on exit ramp lane at end of queue.

Hard shoulder

3rd effect: Traffic capacity is increased by utilization of hard shoulders

Hard shoulder

Hard shoulder capacity is not utilized

Hard shoulder capacity reduces congestion during peak hours

Tackling congestion must start with making best use of existing road infrastructure.

Cost-efficient enforcement of these proposed rules is the key to deployment success.

Recent technology breakthroughs make cost-efficient enforcement possible.

Hard shoulder

200 meters

Hard shoulder

Broadband power-line data link Laser scanners for

lane monitoring

Lamp-pole installation

License plate recognition camera

for vehicle matching

Hard shoulder

Hard shoulder

Vehicle distance is measured by time-of-flight measurement

at 10 cm accuracy. Rate of distance change reveals

standstill or slow vehicles

Each laser-scanner tracks all vehicles’ position for more than

100 meters range, under all weather and lighting conditions

Hard shoulder

Hard shoulder

200 Mbits/s capability

Ethernet interfaces

Lightning protected outdoors equipment

Distance between nodes up to 400 meters

Nodes can be chained for bridged data forwarding

Power-line communications units are also installed onto lamp-poles, creating an instantaneous broadband network.

Terminating power-line gateways can be directly connected to fiber (G-PON data transport).

Infrastructure enforces good driving:

- Vehicles drive slowly in hard shoulder- Inner lanes are for transit driving

- No excessive lane switching- No queue skipping

Many variations of this solution are possible - customers may select most suitable one:

- Laminar traffic flows with Dynamic hard shoulder use- Only Laminar traffic flows / Only Dynamic hard shoulder use

- Innermost lane is tolled express lane... further varieties of above options

Most importantly, enforcement scheme must be acceptable to drivers

THR-452: You are driving over 20 mi/h on hard shoulder!

THR-452: You are skipping exit queue!

THR-452: You have been repeatedly driving short distances in

middle lane!Option 1: Instant

VMS warningOption 2:

warning letterOption 3:

fine

Overview of other congestion management approaches’ deployment aspects

✓Can be quickly deployed

✓Effective

✓Moderate capital requirement

๏Overall traffic capacity is not increased

๏Drivers dislike the idea of being priced off the road

Congestion Pricing (Tolling)

✓ Increases traffic capacity

✓Appealing to public

๏Low initial matching rate and congestion reduction rate

๏Psychology barrier for many drivers

๏Costly tracking box, few mobiles good for auto-tracking

Matched Ride Sharing

✓ Increases traffic capacity in centers

✓Suited for city center

๏Amount and security of P+R parking may be low

๏Public transport is sparse in some cities

๏Mostly applies just to periphery-to-center journeys

Partial use of Public Transport

Deployment aspects of this solution

✓ Increases traffic capacity

✓Can be quickly deployed, with immediate effect

✓Effective congestion alleviation, as it applies to all traffic over deployed road segment

✓Moderate capital requirement

✓Appealing to public, especially in contrast to risks created by hard-shoulder use without proper control (e.g. I-95 Boston loop)

Laminar traffic flows and Dynamic hard shoulder utilization

Hard shoulder

Hard shoulder

Traffic dependent speed limit for optional traffic flow is dynamically

calculated and informed via VMS signs

Optional future extensions

Ramp metering ensures safe highway entry

Traffic engineering is taken to the next level!

Recent laser-scanner and power-line communication technologies make it possible to smooth traffic flows

cost-efficiently!

Everyone benefits from the extra lane capacity and less turbulent driving

Smooth and laminar traffic flow carries more dense traffic!