Traffic Congestion Analysis & Ramp Improvement Proposals

Overview

A detailed discussion was held to address severe congestion around a commercial complex and its adjacent interchanges. The key issues identified are high traffic volumes (≈ 7,300 vehicles), excessive weaving between entry and exit ramps, limited alternative routes, and inadequate lane capacity. The main proposal is to construct a new ramp that separates entry and exit flows, thereby reducing weaving and improving traffic throughput. Various sites were examined, and alternative solutions such as lane reconfiguration, underground conversion, and bus‑lane enhancements were considered.

Main Topics

1. Traffic Volume & Congestion Causes

High peak traffic: The commercial complex experiences a peak volume of 7,300 vehicles, heavily dominated by large trucks.
Short distance between entry/exit points: Entry and exit ramps are closely spaced, forcing vehicles to weave.
Limited alternative routes: Other access points have poor connectivity, making the congested area the only viable option.

2. Proposed Ramp Separation

New dedicated ramp: Separate the exit ramp from the entry ramp, converting the current combined ramp into a single‑direction ramp.
Weaving mitigation: By eliminating the merge point, weaving is reduced, improving safety and flow.
Lane reallocation: The existing entry ramp would then be used exclusively for entry, while the new ramp handles exits.

3. Feasibility & Cost

Cost estimate: Roughly 33 billion KRW for converting an elevated road to an underground structure; considered prohibitive.
Funding constraints: The high cost and low benefit-to‑investment ratio make large‑scale conversion difficult.
Alternative low‑cost measures: Lane reconfiguration, signal optimization, and targeted ramp extensions were discussed as more viable options.

4. Site Analyses

Site	Key Issues	Proposed Action
Industrial Complex	Excessive weaving, high truck volume	New exit ramp, lane separation
Seochang IC / Namdong IC	Short ramp spacing, limited exit capacity	Separate exit ramp, add lane for exit
Bucheon City (Shopping Mall)	Elevated road congestion, high bus‑stop interference	Consider underground conversion (costly) or dedicated bus lanes
Gangil–Toppung IC	Lane reduction from 10 to 4 after toll, causing bottlenecks	Add lane(s) before toll, improve lane merge
Hanam IC (Ramp to Pangyo)	Signal‑controlled ramp causing 10‑km queues	Remove signal, extend ramp, add dedicated exit lane
Bridge Interchanges (Dongjak, Han River)	Limited exit ramps, high bus‑stop congestion	Add new exit ramp, create dedicated bus lane, re‑align traffic flow

5. Alternative Solutions

Underground conversion: Feasible but expensive; not prioritized.
Bus‑lane additions: Dedicated bus lanes could reduce congestion at bus‑stop heavy areas.
Signal optimization: Adjusting signal timing at critical intersections can alleviate queues.
Lane reconfiguration: Reducing or adding lanes in specific sections to match demand.

Opinions & Perspectives

Stakeholder	Viewpoint
Traffic Engineers	New dedicated ramp is the most effective way to reduce weaving and improve safety.
Cost Analysts	High‑cost projects like underground conversion are not justifiable given the limited benefit.
Local Residents	Prefer solutions that minimize construction disruption and preserve existing infrastructure.
Bus Operators	Dedicated bus lanes and better signal timing would reduce delays for public transport.

Key Takeaway: Separating entry and exit flows through a new ramp is the most balanced solution, offering significant congestion relief without the prohibitive costs of large‑scale structural changes.

Q&A Highlights

Question	Answer
Will a new ramp solve the congestion?	Yes, by eliminating weaving and allowing dedicated exit flow, throughput improves markedly.
What is the cost of converting an elevated road underground?	Approximately 33 billion KRW, considered too high relative to expected benefits.
Are there cheaper alternatives?	Lane reconfiguration, signal optimization, and targeted ramp extensions are lower‑cost options.
How will bus traffic be affected?	Dedicated bus lanes and better signal timing can reduce delays at congested intersections.
What about safety?	Separating ramps reduces weaving, lowering collision risk and improving overall safety.

Conclusion:
The consensus is that constructing a dedicated exit ramp, combined with selective lane reconfiguration and signal optimization, offers the most effective and cost‑efficient solution to the congestion problem around the commercial complex and its surrounding interchanges. Large‑scale underground conversion is deemed unnecessary and financially impractical.

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