Metering combined with road pricing reduces trip time and emissions but retains the equity of free entry

Submitted by john on Sun, 15/12/2019 - 19:56

Queue Jumping Rationale
Metering prevents congestion but produces or retains a metering queue. The most critical intersection for the southbound traffic in Hoddle St is at Victoria St, but the metering must be cascaded through successive intersections to constrain the queue 2km upstream at the end of the Eastern Fwy, otherwise the queued lanes plus the lanes required for priority traffic will create a greater restriction.

Demand will always be constrained by delay at the metering queue. This delay wastes time for those caught in the queue and the queue increases the CO2 emissions, both of which should be avoided to the greatest extent possible. 90% queue jumping drops the CO2 emissions by ~53%.
People whose time is more valuable should be able to jump the queue and the best way to decide who and when that is warranted is to let the user decide with a toll. If the toll is set too high, some valuable trips will not be made. If the toll is set too low, all priority traffic will be delayed. It is difficult to set the toll to have the desired effect.

But if in addition to a toll, a free entry queue was kept, that could be a buffer between the toll being too high and too low. The toll could be set so that priority traffic was rarely delayed, and the delay in the queue would then constrain the demand, but only if necessary to prevent congestion. Free entry via a queue is also desirable for equity.

Area pricing is coarser. If there was area pricing, a queue-jumping toll would still be required, unless the toll was overkill. Area pricing is less selective in toll location and so its constriction will reduce the level of service. It does not have as much equity and does not moderate local traffic within the cordon.

To overcome the political negatives, the toll should be installed for three months and then removed. Users should be polled to measure acceptance and if strongly endorsed, the tolled queue-jump reinstated.

The southern half of a diverging diamond interchange of Hoddle St with the Eastern Fwy is shown. Three lanes from the Eastern Fwy are proposed to be tolled and two retained for a free entry queue. Priority lanes in Hoddle St are not proposed. Note that a new priority entry is also proposed from the north. The toll should be pitched low for maximum uptake, saving time, estimated at $1.50 to save 15 minutes, and reducing pollution.

If the trip via the queued lanes on Eastern Fwy is reduced from 40 to 23 minutes, demand from Eastern Fwy grows to 96 vehicles/cycle. Metered capacity of Hoddle St is 110 v/c total and 38 v/c enter, metered plus queued free entry, from the north, leaving 72 v/c to come from Eastern Fwy. The toll is set so up to 64 v/c queue jump, and the balance of the 96, 32 v/c, is added to the queue. At least 8 v/c will be discharged from the queue, plus any shortfall from the 38 and the 64 for each cycle. Signals for each lane meter the flow, usually clearing the three jumping lanes each cycle and the balance comes from two queued lanes.

Queue jumping is also known as congestion chargingFasTrak, and high occupancy toll (HOT) lanes and is a form of road pricing where there can be a variable toll. Some people don't care so much about trip time, and are equally happy to take the bus, but others have greater urgency, so user choice should at least be available, and it can cut emissions in half. Huge benefits would accrue to the community from faster trips, and there is still free access.