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Mobile QR Code QR CODE : Journal of the Korean Society of Civil Engineers

  1. ์„œ์šธ๋Œ€ํ•™๊ต ๊ณต๊ณผ๋Œ€ํ•™ ๊ฑด์„คํ™˜๊ฒฝ๊ณตํ•™๋ถ€ ๋ฐ•์‚ฌ๊ณผ์ • (Seoul National University)
  2. ์„œ์šธ๋Œ€ํ•™๊ต ๊ณต๊ณผ๋Œ€ํ•™ ๊ฑด์„คํ™˜๊ฒฝ๊ณตํ•™๋ถ€ ์„์‚ฌ๊ณผ์ • (Seoul National University)
  3. ์„œ์šธ๋Œ€ํ•™๊ต ๊ณต๊ณผ๋Œ€ํ•™ ๊ฑด์„คํ™˜๊ฒฝ๊ณตํ•™๋ถ€ ๋ฐ•์‚ฌ๊ณผ์ • (Seoul National University)
  4. ์„œ์šธ๋Œ€ํ•™๊ต ๊ณต๊ณผ๋Œ€ํ•™ ๊ฑด์„คํ™˜๊ฒฝ๊ณตํ•™๋ถ€ ๋ถ€๊ต์ˆ˜ (Seoul National University)


Two-fluid model, ๊ฑฐ์‹œ๊ตํ†ต๋ฅ˜, ๋„์‹œ๊ฐ€๋กœ๋ง, ๊ตํ†ต๊ณตํ•™, ํƒ์‹œ DTG ์ž๋ฃŒ
Two-fluid model, Macroscopic traffic flow, Urban network, Traffic engineering, Taxi digital tacho graph data

  • 1. ์„œ ๋ก 

  • 2. ๋ฌธํ—Œ๊ณ ์ฐฐ

  • 3. ๋ฐฉ๋ฒ•๋ก 

  •   3.1 ์‹œ๊ฐ„๋Œ€๋ณ„ ๋„คํŠธ์›Œํฌ ๋‚ด ์ฐจ๋Ÿ‰ ์†๋„๊ตฌ์„ฑ

  •   3.2 Two-fluid Model

  •   3.3 Two-fluid Model ์ ์šฉ ๋ฐฉ๋ฒ•๋ก 

  •   3.4 ์—ฐ๊ตฌ ๋ฒ”์œ„

  • 4. ์—ฐ๊ตฌ๊ฒฐ๊ณผ

  • 5. ๊ฒฐ ๋ก 

1. ์„œ ๋ก 

๊ตํ†ต์ˆ˜์š”์˜ ์ฆ๊ฐ€๋กœ ์ธํ•œ ๊ตํ†ตํ˜ผ์žก์€ ์‹œ๊ฐ„์ด ํ๋ฆ„์— ๋”ฐ๋ผ ๋”์šฑ ์‹ฌ๊ฐํ•œ ๊ตํ†ต๋ฌธ์ œ๋กœ ๋Œ€๋‘๋˜๊ณ  ์žˆ์œผ๋ฉฐ, ์ด๋Š” ๊ตํ†ต๊ณตํ•™์ž๋“ค์ด ํ•ด๊ฒฐํ•ด์•ผ ํ•  ์ด์Šˆ ์ค‘ ํ•˜๋‚˜์ด๋‹ค. ์‹œ์Šคํ…œ ๊ณต๊ธ‰ ์ธก๋ฉด์—์„œ ๋„๋กœ์˜ ์—ฐ์žฅ ๋ฐ ์ฐจ๋กœ ์ˆ˜๋ฅผ ๋Š˜๋ฆฌ๋Š” ๊ฒƒ์€ ํ•œ๊ณ„๊ฐ€ ์žˆ์œผ๋ฉฐ, ํ˜ผ์žกํ†ตํ–‰๋ฃŒ, ์‹ ํ˜ธ์šด์˜๊ฐœ์„ , ๋žจํ”„๋ฏธํ„ฐ๋ง ๋“ฑ์˜ ๊ตํ†ต์ฒด๊ณ„ ์ข…ํ•ฉ๊ด€๋ฆฌ(Transportation System Management; TSM)๋ฅผ ํ†ตํ•ด ํ•ด๊ฒฐํ•˜๋ ค๋Š” ์‹œ๋„๊ฐ€ ๋งŽ์ด ์ง„ํ–‰๋˜์–ด ์™”๋‹ค. ๊ตญ๋‚ด์—์„œ๋Š” 1991๋…„ ๊ฒฝ์ฐฐ์ฒญ์„ ์ฃผ์ฒด๋กœ ํ•˜์—ฌ ์ฒจ๋‹จ ๊ตํ†ต์‹ ํ˜ธ์ฒด๊ณ„ ๊ฐœ๋ฐœ์„ ์ง„ํ–‰ํ•˜์˜€์œผ๋ฉฐ, 1997๋…„ ์‹ค์‹œ๊ฐ„ ์‹ ํ˜ธ์ œ์–ด์‹œ์Šคํ…œ(Cycle, offset, split model for Seoul; COSMOS)์„ ์„œ์šธ์‹œ 61๊ฐœ ๊ต์ฐจ๋กœ์— ์‹œ๋ฒ”์šด์˜ํ•œ ๋ฐ” ์žˆ๋‹ค(Lee et al., 2002).

์ƒˆ๋กœ์šด ์‹ ํ˜ธ์šด์˜ ์‹œ์Šคํ…œ์„ ๋„์ž…ํ•˜๊ธฐ ์ „์—๋Š” ์‹œ๋ฎฌ๋ ˆ์ด์…˜์„ ํ†ตํ•œ ์‚ฌ์ „ํ‰๊ฐ€๊ฐ€ ์ง„ํ–‰๋˜์–ด์•ผ ํ•˜๋ฉฐ, ๋„์ž… ํ›„์—๋Š” ํ…Œ์ŠคํŠธ๋ฒ ๋“œ๋ฅผ ํ†ตํ•œ ํšจ๊ณผ๋ถ„์„์ด ์ˆ˜ํ–‰๋˜์–ด์•ผ ํ•œ๋‹ค. ์ƒˆ๋กœ์šด ์‹ ํ˜ธ์šด์˜ ์‹œ์Šคํ…œ์„ ํ‰๊ฐ€ํ•˜๊ธฐ ์œ„ํ•œ ์ง€ํ‘œ์— ๋Œ€ํ•œ ์—ฐ๊ตฌ๋Š” ๋งŽ์ด ์ง„ํ–‰๋˜์–ด์™”๋‹ค. ํ‰๊ท  ํ†ตํ–‰์‹œ๊ฐ„, ์ด ํ†ตํ–‰์‹œ๊ฐ„, ํ‰๊ท  ์ง€์ฒด์‹œ๊ฐ„, ์ด ์ง€์ฒด์‹œ๊ฐ„, ํ‰๊ท  ํ†ตํ–‰์†๋„ ๋“ฑ์˜ ํ†ตํ–‰์‹œ๊ฐ„(์†๋„) ๊ด€๋ จ ์ง€ํ‘œ, ํ†ต๊ณผ๊ตํ†ต๋Ÿ‰, ํฌํ™”๋„ ๋“ฑ์˜ ๊ตํ†ต๋Ÿ‰ ๊ด€๋ จ ์ง€ํ‘œ๊ฐ€ ๋Œ€ํ‘œ์ ์ธ ๊ตํ†ต๋ฅ˜ ์ง€ํ‘œ๋ผ ํ•  ์ˆ˜ ์žˆ์œผ๋ฉฐ, OSI (Oversaturation Severity Index), SOSI (Spatial OSI), TOSI (Temporal OSI) ๋“ฑ์˜ ์‹ ํ˜ธ์šด์˜ ๊ด€๋ จ ์ง€ํ‘œ๋“ค๋„ ์‹ ํ˜ธ์šด์˜์ฒด๊ณ„๋ฅผ ํ‰๊ฐ€ํ•˜๋Š”๋ฐ ๋งŽ์ด ์“ฐ์—ฌ์™”๋‹ค(Hu et al., 2013). ์ด๋Ÿฌํ•œ ์ง€ํ‘œ๋“ค์€ ๊ตํ†ต์ƒํ™ฉ์„ ์ง๊ด€์ ์œผ๋กœ ํ‘œํ˜„ํ•  ์ˆ˜ ์žˆ๋Š” ์žฅ์ ์€ ์žˆ์œผ๋‚˜ ๋„คํŠธ์›Œํฌ ํ˜น์€ ์‹ ํ˜ธ์šด์˜์ฒด๊ณ„ ์ž์ฒด๋ฅผ ํ‰๊ฐ€ํ•˜๊ธฐ์—๋Š” ๋‹ค์†Œ ๋ฌด๋ฆฌ๊ฐ€ ์žˆ๋‹ค.

Herman and Prigogine(1979)์— ์˜ํ•ด ์ œ์•ˆ๋œ Two-fluid Model์€ ๊ฑฐ์‹œ์  ๊ตํ†ต๋ฅ˜์˜ ๊ตํ†ตํŠน์„ฑ์„ ๋‚˜ํƒ€๋‚ผ ์ˆ˜ ์žˆ๋Š” ์ง€ํ‘œ ์ค‘ ๊ตํ†ต๋ฅ˜ ์ด๋ก ์œผ๋กœ ์ •๋ฆฝ๋˜์–ด ํ™œ์šฉ๋˜๋Š” ๋Œ€ํ‘œ์ ์ธ ์ง€ํ‘œ์ด๋‹ค(Lee, 2003a). Two-fluid Model์€ ๋„คํŠธ์›Œํฌ์˜ ์ •์ง€์ฐจ๋Ÿ‰ ๋น„์œจ๊ณผ ํ‰๊ท ์ฃผํ–‰์†๋„์˜ ๊ด€๊ณ„๋ฅผ ๊ทœ๋ช…ํ•˜๋Š” ๊ฒƒ์— ๊ธฐ์ดˆํ•œ๋‹ค. ๊ทธ๋Ÿฌ๋‚˜ ๋„คํŠธ์›Œํฌ์˜ ์ฐจ๋Ÿ‰์„ ์ •์ง€์ฐจ๋Ÿ‰๊ณผ ์ฃผํ–‰์ฐจ๋Ÿ‰์˜ ๋‘ ๊ฐ€์ง€๋กœ ๊ตฌ๋ถ„ํ•˜๋Š” ๊ฒƒ์—๋Š” ํ•œ๊ณ„๊ฐ€ ์žˆ์„ ์ˆ˜ ์žˆ๋‹ค. ๋„คํŠธ์›Œํฌ ๋‚ด ์ •์ง€์ฐจ๋Ÿ‰์€ ์‹ ํ˜ธ๊ต์ฐจ๋กœ๋กœ ์ธํ•˜์—ฌ ์ƒ์‹œ ์กด์žฌํ•˜๋ฉฐ, ๋„คํŠธ์›Œํฌ๊ฐ€ ์ •์ฒด์ƒํ™ฉ์ผ ๋•Œ์—๋Š” ์ •์ง€์ฐจ๋Ÿ‰ ๋ฟ๋งŒ ์•„๋‹ˆ๋ผ ์ €์†์ฐจ๋Ÿ‰์˜ ๋น„์œจ ์—ญ์‹œ ์ฆ๊ฐ€ํ•˜๊ฒŒ ๋œ๋‹ค. ๋”ฐ๋ผ์„œ ๋ณธ ์—ฐ๊ตฌ์—์„œ๋Š” ๊ธฐ์กด ์—ฐ๊ตฌ์—์„œ ๋ฐ˜์˜ํ•˜์ง€ ๋ชปํ•˜์˜€๋˜ ์ €์†์ฐจ๋Ÿ‰์˜ ์˜ํ–ฅ์„ ๋ฐ˜์˜ํ•œ Two-fluid Model์„ ์ œ์•ˆํ•˜๊ณ ์ž ํ•œ๋‹ค.

2. ๋ฌธํ—Œ๊ณ ์ฐฐ

Two-fluid Model์€ ์ •์ง€์ฐจ๋Ÿ‰์ด ๋„คํŠธ์›Œํฌ์— ํ•ญ์ƒ ์กด์žฌํ•˜๋Š” ์‹ ํ˜ธ๊ต์ฐจ๋กœ ๋“ฑ์˜ ๋„์‹œ๋ถ€ ๋‹จ์†๋ฅ˜ ๋„คํŠธ์›Œํฌ๋ฅผ ๋ถ„์„ํ•  ๋•Œ ์ฃผ๋กœ ์‚ฌ์šฉ๋˜์–ด์™”๋‹ค(Wu et al., 2011). Two-fluid Model์˜ ํŒŒ๋ผ๋ฏธํ„ฐ์ธ Tm๊ณผ n์€ ๊ฐ๊ฐ โ€˜๋‹จ์œ„๊ฑฐ๋ฆฌ ๋‹น ์ตœ์†Œํ†ตํ–‰์‹œ๊ฐ„โ€™๊ณผ โ€˜๋„คํŠธ์›Œํฌ ์ €ํ•ญ๊ณ„์ˆ˜โ€™๋กœ ๊ฐ๊ฐ ๋„คํŠธ์›Œํฌ์˜ ์„ฑ๋Šฅ๊ณผ ๋„คํŠธ์›Œํฌ์˜ ๊ตํ†ต์ˆ˜์š”์— ๋Œ€ํ•œ ์„ฑ๋Šฅ์˜ ๋ณ€ํ™”์ •๋„๋ฅผ ์˜๋ฏธํ•œ๋‹ค. ๋”ฐ๋ผ์„œ ์ด ํŒŒ๋ผ๋ฏธํ„ฐ๋“ค์€ ๋„์‹œ๋ถ€ ๊ฐ€๋กœ๋ง, ์‹ ํ˜ธ์šด์˜ ์‹œ์Šคํ…œ์„ ํ‰๊ฐ€ํ•˜๋Š”๋ฐ ๋„๋ฆฌ ์‚ฌ์šฉ๋˜์—ˆ์œผ๋ฉฐ, Tm๊ณผ n์˜ ๊ฐ’์ด ๋‚ฎ์„์ˆ˜๋ก ๋„คํŠธ์›Œํฌ์˜ ์„ฑ๋Šฅ์ด ์ข‹๋‹ค๋Š” ๊ฒƒ์„ ์˜๋ฏธํ•œ๋‹ค. Herman et al.(1979, 1988)์€ ๋Ÿฐ๋˜, ๋Œˆ๋Ÿฌ์Šค ๋“ฑ ์—ฌ๋Ÿฌ ๋„์‹œ๋ฅผ ๋น„๊ต๋ถ„์„ ํ•˜์˜€์œผ๋ฉฐ, Jones and Farhat(2004)์€ ๋ฏธ๊ตญ ์˜ค๋งˆํ•˜์˜ ๋„์‹œ๋ถ€ ๊ฐ„์„ ๋„๋กœ๋ง์— ๋Œ€ํ•œ Two-fluid Model์ด ์ ์šฉ๋  ์ˆ˜ ์žˆ์Œ์„ ๋ฐํžŒ ๋ฐ” ์žˆ๋‹ค. Wu et al. (2011)์€ Two-fluid Model์˜ ํŒŒ๋ผ๋ฏธํ„ฐ๋“ค์„ ํ†ตํ•˜์—ฌ SCATS (Sydney Coordinated Adaptive Traffic System)์™€ ACTRA์˜ ์‹œ์Šคํ…œ์„ ๋น„๊ต๋ถ„์„ํ•˜์˜€๊ณ , ๊ตญ๋‚ด์—์„œ๋Š” Lee et al.(2003b)์€ ROTIS ์ž๋ฃŒ๋ฅผ ์‚ฌ์šฉํ•˜์—ฌ ์„œ์šธ์‹œ ๊ฐ•๋‚จ๊ตฌ์˜ ๋„คํŠธ์›Œํฌ ์„ฑ๋Šฅ์„ ํ•ด์™ธ ์ฃผ์š” ๋„์‹œ๋“ค๊ณผ ๋น„๊ตํ•˜์˜€์œผ๋ฉฐ, Jeong et al.(2009)์€ ๊ตํ†ต์‹œ์Šคํ…œ ๊ฐœ์„ ์— ๋”ฐ๋ฅธ ํšจ๊ณผ๋ฅผ Tm๊ณผ n์„ ํ†ตํ•ด ์‚ฐ์ •ํ•œ ๋ฐ” ์žˆ๋‹ค.

Two-fluid Model์˜ ํŒŒ๋ผ๋ฏธํ„ฐ์ธ Tm๊ณผ n์— ๋ฏธ์น˜๋Š” ์˜ํ–ฅ์€ ๋ชจ๋ธ์˜ ์ œ์•ˆ ์ดํ›„๋ถ€ํ„ฐ ํ˜„์žฌ๊นŒ์ง€ ํ™œ๋ฐœํ•˜๊ฒŒ ์ด๋ฃจ์–ด์ ธ ์™”๋‹ค. Herman et al.(1988)์€ ๋กœ์–ด๋…ธํฌ์™€ ์˜ค์Šคํ‹ด์˜ ์ค‘์‹ฌ ์—…๋ฌด์ง€๊ตฌ(Central Business District; CBD)์—์„œ ์šด์ „์ž๋“ค์˜ ์„ฑํ–ฅ(Aggressive, Normal, Conservative)๊ณผ Two-fluid Model ํŒŒ๋ผ๋ฏธํ„ฐ์˜ ๊ด€๊ณ„์— ๋Œ€ํ•ด ์—ฐ๊ตฌํ•˜์˜€๋‹ค. ์šด์ „์ž์˜ ์šด์ „์„ฑํ–ฅ์ด ๊ณต๊ฒฉ์ (Aggressive)์ผ์ˆ˜๋ก Tm์€ ๊ฐ์†Œํ•˜๋ฉฐ, n์€ ์ฆ๊ฐ€ํ•˜๋Š” ๊ฒฝํ–ฅ์„ ๋ณด์ด๋Š” ๊ฒƒ์„ ํ™•์ธํ•˜์˜€๋‹ค. Lee et al.(2003)์€ ROTIS ์ž๋ฃŒ๋ฅผ ํ™œ์šฉํ•˜์—ฌ ๊ฐ•์„ค์ด Two-fluid Model์˜ ํŒŒ๋ผ๋ฏธํ„ฐ์— ๋ฏธ์น˜๋Š” ์˜ํ–ฅ์— ๋Œ€ํ•ด ์—ฐ๊ตฌํ•˜์˜€๋‹ค. ๊ฐ•์„ค์‹œ Tm์€ ์œ ์˜๋ฏธํ•œ ๋ณ€ํ™”๋ฅผ ๋ณด์ด์ง€ ์•Š์•˜์œผ๋‚˜, n์€ ํ™•์—ฐํžˆ ์ฆ๊ฐ€ํ•˜๋Š” ๊ฒƒ์„ ํ™•์ธํ•˜์˜€๋‹ค. ์ฆ‰, ๊ตํ†ต๋Ÿ‰์ด ์ ์„ ๋•Œ์—๋Š” Tm์˜ ๋ณ€ํ™”๊ฐ€ ์ ์œผ๋ฏ€๋กœ ๊ฐ•์„ค์€ ๊ฐ€๋กœ๋ง์˜ ์„ฑ๋Šฅ์—๋Š” ํฐ ์˜ํ–ฅ์„ ๋ฏธ์น˜์ง€ ์•Š์œผ๋ฉฐ, n์ด ๋†’๊ธฐ ๋•Œ๋ฌธ์— ๊ตํ†ต์ˆ˜์š”๊ฐ€ ๋†’์„ ๋•Œ ๊ฐ•์„ค์˜ ์˜ํ–ฅ์ด ํฌ๊ฒŒ ๋‚˜ํƒ€๋‚˜๋Š” ๊ฒƒ์„ ๋ฐํ˜”๋‹ค. Pande et al.(2015)์€ California์˜ ๋‚จ๋…€์šด์ „์ž๋ณ„ GPS ์ฃผํ–‰์ž๋ฃŒ๋ฅผ ํ†ตํ•ด ๋‚จ๋…€๊ฐ„์˜ Two-fluid Model ํŒŒ๋ผ๋ฏธํ„ฐ๋ฅผ ๊ฐ๊ฐ ์‚ฐ์ •ํ•˜์˜€๊ณ , ์ด๋ฅผ ํ†ตํ•ด ๋‚จ๋…€์˜ ์šด์ „์„ฑํ–ฅ์„ ๋น„๊ตํ•˜์˜€๋‹ค. ๋น„๊ต ๊ฒฐ๊ณผ ์—ฌ์„ฑ์šด์ „์ž์˜ n์ด ๋†’์€ ๊ฒฐ๊ณผ๋ฅผ ๋ณด์˜€์œผ๋ฉฐ, ์ด๋ฅผ ํ†ตํ•ด ์—ฌ์„ฑ์šด์ „์ž๋“ค์ด ๋‚จ์„ฑ์šด์ „์ž๋“ค์— ๋น„ํ•ด ๋” ๊ณต๊ฒฉ์ (Aggressive)์ด๋ผ๋Š” ๊ฒƒ์„ ํŒŒ์•…ํ•˜์˜€๋‹ค. Dixit et al.(2011)์€ Two-fluid Model ํŒŒ๋ผ๋ฏธํ„ฐ๋“ค๊ณผ ๊ตํ†ต์‚ฌ๊ณ ์œ ํ˜• ๊ฐ„์˜ ์ƒ๊ด€๊ด€๊ณ„๋ฅผ ๋ถ„์„ํ•˜์˜€๋‹ค. ๋ฏธ๊ตญ Florida์˜ 8๊ฐœ์˜ ๊ฐ„์„ ๋„๋กœ์—์„œ ๊ฐ๊ฐ Two-fluid Model์˜ ํŒŒ๋ผ๋ฏธํ„ฐ๋ฅผ ์‚ฐ์ •ํ•˜์˜€๊ณ , ๊ฐ„์„ ๋„๋กœ ๋ณ„ ์•ˆ์ „์ง€ํ‘œ๋“ค์„ ์‚ฐ์ •ํ•˜์—ฌ Two-fluid Model ํŒŒ๋ผ๋ฏธํ„ฐ์™€ ๊ตํ†ต์‚ฌ๊ณ ์œ ํ˜•์˜ ์ƒ๊ด€๊ด€๊ณ„๋ฅผ ๋ถ„์„ํ•˜์˜€๋‹ค. ๋ถ„์„๊ฒฐ๊ณผ โ€œRear-end crash rateโ€์™€ โ€œAngle crash rateโ€๊ฐ€ Two-fluid Model ํŒŒ๋ผ๋ฏธํ„ฐ์™€ ๋ฐ€์ ‘ํ•œ ๊ด€๊ณ„๊ฐ€ ์žˆ๋Š” ๊ฒƒ์„ ํŒŒ์•…ํ•˜์˜€๊ณ , ๋ณธ ์—ฐ๊ตฌ๊ฒฐ๊ณผ๋Š” ์ง€์—ญ๋ณ„ Two-fluid Model ํŒŒ๋ผ๋ฏธํ„ฐ๋ฅผ ํ†ตํ•ด, ์ง€์—ญ๋ณ„๋กœ ์„œ๋กœ ๋‹ค๋ฅธ ์•ˆ์ „๋Œ€์ฑ…์„ ๋งˆ๋ จํ•  ์ˆ˜ ์žˆ์Œ์„ ์‹œ์‚ฌํ•˜๊ณ  ์žˆ๋‹ค.

Two-fluid Model์€ ๊ฑฐ์‹œ๊ตํ†ต๋ฅ˜์˜ ๋Œ€ํ‘œ์  ์ง€ํ‘œ์ธ ํ‰๊ท ์†๋„, ๊ตํ†ต๋Ÿ‰, ๋ฐ€๋„๋ฅผ ์‚ฐ์ถœํ•˜๋Š”๋ฐ ์‚ฌ์šฉ๋œ ๋ฐ” ์žˆ๋‹ค. Lu et al.(2018)์€ ํƒ์‹œ GPS ์ž๋ฃŒ๋ฅผ ํ†ตํ•œ ๋„คํŠธ์›Œํฌ์˜ MFD (Macroscopic Fundamental Diagram) ์ถ”์ •์— ๋Œ€ํ•ด ์—ฐ๊ตฌํ•˜์˜€๋‹ค. ๋„คํŠธ์›Œํฌ ๋‚ด ์ „์ฒด ์ฐจ๋Ÿ‰์˜ ํ‰๊ท  ์ด๋™๊ฑฐ๋ฆฌ์™€ ํƒ์‹œ์˜ ํ‰๊ท  ์ด๋™๊ฑฐ๋ฆฌ๊ฐ€ ๋™์ผํ•˜๋‹ค๋Š” ๊ฐ€์ •์„ ๊ธฐ๋ฐ˜์œผ๋กœ ํƒ์‹œ ์ฐจ๋Ÿ‰์˜ ๊ถค์ ์„ ํ†ตํ•ด ๋„คํŠธ์›Œํฌ์˜ ๊ตํ†ต๋Ÿ‰๊ณผ ๋ฐ€๋„๋ฅผ ์‚ฐ์ •ํ•˜์˜€๊ณ , ๋„คํŠธ์›Œํฌ ๋‚ด ์ •์ง€์ฐจ๋Ÿ‰์˜ ๋น„์œจ ๋ณ„ ํ‰๊ท ์†๋„์™€ ๊ตํ†ต๋Ÿ‰์„ ์ถ”์ •ํ•˜์—ฌ ๋„คํŠธ์›Œํฌ์˜ MFD๋ฅผ ๊ตฌํ•˜๋Š” ๋ฐฉ์•ˆ์— ๋Œ€ํ•ด ์—ฐ๊ตฌํ•˜์˜€๋‹ค. Artimy(2007)์€ Two-fluid Model์˜ ๋‹จ์œ„๊ฑฐ๋ฆฌ๋‹น ํ‰๊ท  ์ฃผํ–‰์‹œ๊ฐ„๊ณผ ๋‹จ์œ„๊ฑฐ๋ฆฌ๋‹น ํ‰๊ท  ์ •์ง€์‹œ๊ฐ„์„ ํ†ตํ•˜์—ฌ ๋„คํŠธ์›Œํฌ ๋‚ด ํ‰๊ท ๋ฐ€๋„๋ฅผ ์‚ฐ์ •ํ•˜๋Š” ๋ฐฉ์•ˆ์— ๋Œ€ํ•ด ์—ฐ๊ตฌํ•˜์˜€๋‹ค. ๋˜ํ•œ Two-fluid Model์˜ ๊ธฐ๋ณธ ๊ฐ€์ •๊ณผ Fundamental Equation (q=uk)์—์„œ ฮผ์™€ q๋ฅผ ์ •์ง€์ฐจ๋Ÿ‰์˜ ๋น„์œจ๊ณผ ์ฃผํ–‰์ฐจ๋Ÿ‰์˜ ๋น„์œจ์„ ํ†ตํ•ด ์‚ฐ์ •ํ•˜๊ณ , ์ด๋ฅผ ํ†ตํ•ด ๋„คํŠธ์›Œํฌ์˜ Local Density๋ฅผ ๊ตฌํ•˜์˜€๋‹ค. Yao and Wang(2008)์€ Two-fluid Model์˜ ํŒŒ๋ผ๋ฏธํ„ฐ๋ฅผ ํ†ตํ•ด ๋งํฌ์˜ ๋“ฑ๊ฐ€ ๋Œ€๊ธฐ๊ธธ์ด๋ฅผ ๊ตฌํ•˜๋Š” ๋ฐฉ์•ˆ์— ๋Œ€ํ•ด ์—ฐ๊ตฌํ•˜์˜€๋‹ค. ๊ฐ ๋งํฌ์˜ ์œ ์ž…์ฐจ๋Ÿ‰๊ณผ ์œ ์ถœ์ฐจ๋Ÿ‰์„ ํ†ตํ•ด ํ•ด๋‹น ๋งํฌ์˜ ๋ฐ€๋„๋ฅผ ์‚ฐ์ •ํ•˜๊ณ , ์ดํ›„ ์ฐจ๋Ÿ‰์˜ ์ •์ง€๋น„์œจ์„ ํ†ตํ•ด ๋“ฑ๊ฐ€ ๋Œ€๊ธฐ๊ธธ์ด๋ฅผ ๊ตฌํ•  ์ˆ˜ ์žˆ๋Š” ๋ฐฉ์•ˆ์„ ์ œ์‹œํ•˜์˜€๋‹ค. Lu et al.(2016)์€ ๋„์‹œ๋ถ€๋ฅผ 1ร—1 km์˜ ์ •์‚ฌ๊ฐํ˜• ํ˜•ํƒœ๋กœ ๊ตฌ๋ถ„ํ•œ ํ›„, ๊ฐ ๊ตฌ์—ญ๋ณ„ Tm์„ ์‚ฐ์ •ํ•˜์˜€๋‹ค. ๋ณธ ์—ฐ๊ตฌ์—์„œ Tm์€ ๊ฐ ๊ตฌ์—ญ์„ ํ†ต๊ณผํ•˜๋Š”๋ฐ ์†Œ์š”๋˜๋Š” ์ตœ์†Œ ํ†ตํ–‰์‹œ๊ฐ„์„ ์˜๋ฏธํ•˜๋ฏ€๋กœ, Dijkstra ์•Œ๊ณ ๋ฆฌ์ฆ˜์„ ํ™œ์šฉํ•˜์—ฌ ๊ฐ ๊ตฌ์—ญ๋ณ„ O/D ํ†ตํ–‰์‹œ๊ฐ„ ํ–‰๋ ฌ(O/D travel time matrix)๋ฅผ ๊ตฌํ•˜์˜€์œผ๋ฉฐ, O/D ํ†ตํ–‰์‹œ๊ฐ„ ํ–‰๋ ฌ์€ ํ–ฅํ›„ ๋™์  ํ†ตํ–‰๋ฐฐ์ •(dynamic traffic assignment)์„ ์œ„ํ•œ ์ตœ๋‹จ๊ฒฝ๋กœ๋ฅผ ์ฐพ๋Š” ๊ฒƒ์— ํ™œ์šฉ๋  ์ˆ˜ ์žˆ์Œ์„ ๋ฐํ˜”๋‹ค. Two-fluid Model์˜ ์ œ์•ˆ ์ดํ›„ Model์˜ ํŒŒ๋ผ๋ฏธํ„ฐ์— ๋ฏธ์น˜๋Š” ์š”์†Œ์™€ Model์˜ ํŒŒ๋ผ๋ฏธํ„ฐ๋ฅผ ํ™œ์šฉํ•œ ๊ตํ†ต๋ฅ˜ ๋ถ„์„์— ๋Œ€ํ•ด์„œ๋Š” ๋งŽ์€ ์—ฐ๊ตฌ๊ฐ€ ์ง„ํ–‰๋˜์–ด์™”์œผ๋‚˜, Model์˜ ๋ฐœ์ „์— ๊ด€ํ•œ ์—ฐ๊ตฌ๋Š” ํ™œ๋ฐœํžˆ ์ง„ํ–‰๋˜์ง€ ์•Š์•˜๋‹ค.

3. ๋ฐฉ๋ฒ•๋ก 

3.1 ์‹œ๊ฐ„๋Œ€๋ณ„ ๋„คํŠธ์›Œํฌ ๋‚ด ์ฐจ๋Ÿ‰ ์†๋„๊ตฌ์„ฑ

๋„คํŠธ์›Œํฌ์˜ ๊ตํ†ต์ˆ˜์š”๊ฐ€ ์ฆ๊ฐ€ํ•จ์— ๋”ฐ๋ผ ๋„คํŠธ์›Œํฌ ๋‚ด ํ‰๊ท ํ†ตํ–‰์†๋„๋Š” ๊ฐ์†Œํ•œ๋‹ค. ์ด์— ๋”ฐ๋ผ ๋„คํŠธ์›Œํฌ ๋‚ด ์ •์ง€์ฐจ๋Ÿ‰์˜ ๋น„์œจ์€ ์ฆ๊ฐ€ํ•˜๋ฉฐ, ์ €์†์ฐจ๋Ÿ‰์˜ ๋น„์œจ๋„ ์ฆ๊ฐ€ํ•œ๋‹ค. 2018๋…„ 9์›” DGPS ์ฃผํ–‰์‹คํ—˜ ๊ฒฐ๊ณผ์— ๋”ฐ๋ฅด๋ฉด ์‹œ๊ฐ„๋Œ€๋ณ„ ๊ตํ†ตํŠน์„ฑ์€ Fig. 1๊ณผ ๊ฐ™์ด ๋„คํŠธ์›Œํฌ๊ฐ€ ์ž์œ ์†๋„์— ๊ฐ€๊นŒ์šธ ๋•Œ๋Š” ์‹ ํ˜ธ์ œ์–ด์— ์˜ํ•œ ์ •์ง€๊ฐ€ ๋ฐœ์ƒํ•˜๋ฉฐ, ์ •์ฒด์‹œ์—๋Š” ์‹ ํ˜ธ์™€ ๋Œ€๊ธฐํ–‰๋ ฌ์— ์˜ํ•ด ์ •์ง€์™€ ์ €์†์ฃผํ–‰์ด ๋ฐ˜๋ณต์ ์œผ๋กœ ๋‚˜ํƒ€๋‚˜๋Š” ๊ฒƒ์„ ํ™•์ธํ•˜์˜€๋‹ค. ๋”ฐ๋ผ์„œ ์ €์†์ฃผํ–‰์ฐจ๋Ÿ‰ ์—ญ์‹œ ๋„คํŠธ์›Œํฌ์˜ ๊ตํ†ต์ƒํ™ฉ์„ ๋ถ„์„ํ•  ์ˆ˜ ์žˆ๋Š” ํ•˜๋‚˜์˜ ๋ณ€์ˆ˜๊ฐ€ ๋  ์ˆ˜ ์žˆ์„ ๊ฒƒ์ด๋ฉฐ, ๊ธฐ์กด Two-fluid Model์˜ ์ €์†์ฃผํ–‰์ฐจ๋Ÿ‰์ด ๋„คํŠธ์›Œํฌ์— ๋ฏธ์น˜๋Š” ์˜ํ–ฅ์„ ๋ฐ˜์˜ํ•˜์ง€ ๋ชปํ•œ ํ•œ๊ณ„์ ์„ ๋ณด์™„ํ•  ์ˆ˜ ์žˆ์„ ๊ฒƒ์ด๋‹ค. ๋”ฐ๋ผ์„œ ๋ณธ ์—ฐ๊ตฌ์—์„œ๋Š” ์ •์ง€์ฐจ๋Ÿ‰๋ฟ๋งŒ ์•„๋‹ˆ๋ผ ์ €์†์ฐจ๋Ÿ‰์ด ๋„คํŠธ์›Œํฌ์— ๋ฏธ์น˜๋Š” ์˜ํ–ฅ์„ ๊ณ ๋ คํ•œ Two-fluid Model์„ ์ œ์•ˆํ•˜๊ณ ์ž ํ•œ๋‹ค.

Figure_KSCE_39_1_07_F1.jpg
Fig. 1.

Prove Car Speed Diagram (Gangnam-gu, Seoul, 2018.9.15. 09:00~10:00)

3.2 Two-fluid Model

Two-fluid Model์€ ๋„คํŠธ์›Œํฌ ๋‚ด ํ‰๊ท  ์ฃผํ–‰์†๋„๋Š” ์›€์ง์ด๋Š” ์ฐจ๋Ÿ‰์˜ ๋น„์œจ์— ๋น„๋ก€ํ•œ๋‹ค๋Š” ๊ฐ€์ •์—์„œ ์ถœ๋ฐœํ•œ๋‹ค.

vr=vmร—fmr=vm(1โˆ’fs)n(fr+fs=1) (1)

(Vr: ํ‰๊ท  ์ฃผํ–‰์†๋„, Vm: ์ตœ๋Œ€ ์ฃผํ–‰์†๋„, fs: ์ •์ง€์ฐจ๋Ÿ‰ ๋น„์œจ, fr: ์ฃผํ–‰์ฐจ๋Ÿ‰ ๋น„์œจ, n: ๋„คํŠธ์›Œํฌ ์ €ํ•ญ๊ณ„์ˆ˜)

์ด๋•Œ ๋„คํŠธ์›Œํฌ ๋‚ด ์ •์ง€์ฐจ๋Ÿ‰ ๋น„์œจ์€ ์ฐจ๋Ÿ‰์˜ ๋‹จ์œ„๊ฑฐ๋ฆฌ ๋‹น ํ†ตํ–‰์‹œ๊ฐ„๊ณผ ๋‹จ์œ„๊ฑฐ๋ฆฌ ๋‹น ์ •์ง€์‹œ๊ฐ„์˜ ๋น„์œจ์„ ํ†ตํ•ด ์‚ฐ์ •ํ•  ์ˆ˜ ์žˆ๋‹ค(Herman and Prigogine, 1979).

fs=TsT(T=Ts+Tr) (2)

(Ts: ๋‹จ์œ„๊ฑฐ๋ฆฌ ๋‹น ํ‰๊ท  ์ •์ง€์‹œ๊ฐ„, Tr: ๋‹จ์œ„๊ฑฐ๋ฆฌ ๋‹น ํ‰๊ท  ์ฃผํ–‰์‹œ๊ฐ„, T: ๋‹จ์œ„๊ฑฐ๋ฆฌ ๋‹น ํ‰๊ท  ํ†ตํ–‰์‹œ๊ฐ„)

Eqs. (1) and (2)๋กœ๋ถ€ํ„ฐ ํ‰๊ท  ์ฃผํ–‰์†๋„๋Š” Eq. (3)๊ณผ ๊ฐ™์ด ๋‚˜ํƒ€๋‚ผ ์ˆ˜ ์žˆ์œผ๋ฉฐ, ํ‰๊ท  ํ†ตํ–‰์†๋„๋Š” ์ •์˜๋กœ๋ถ€ํ„ฐ Eq. (4)์™€ ๊ฐ™๋‹ค.

vr=1Tm(1โˆ’fs)n (3)
v=vrร—fr+vsร—fs=vrร—fr (4)

(Tm: ๋‹จ์œ„๊ฑฐ๋ฆฌ ๋‹น ์ตœ์†Œ ํ†ตํ–‰์‹œ๊ฐ„, n: ๋„คํŠธ์›Œํฌ ์ €ํ•ญ๊ณ„์ˆ˜)

๋”ฐ๋ผ์„œ Two-fluid Model์€ ๋‹ค์Œ๊ณผ ๊ฐ™์€ ์‹์œผ๋กœ ํ‘œํ˜„์ด ๋œ๋‹ค.

v=1T=1Tm(1โˆ’fs)nfr (5)
orTmT=(1โˆ’fs)n+1 (6)

Eq. (2)๋ฅผ Eq. (6)์— ๋Œ€์ž…ํ•˜๋ฉด ๋‹ค์Œ๊ณผ ๊ฐ™๋‹ค.

1โˆ’TsT=(TmT)1n+1 (7)

Eq. (7)์„ Ts์— ๋Œ€ํ•ด ํ‘œํ˜„ํ•˜๋ฉด ๋‹ค์Œ๊ณผ ๊ฐ™๋‹ค.

Ts=Tโˆ’T1n+1mT1n+1 (8)

3.3 Two-fluid Model ์ ์šฉ ๋ฐฉ๋ฒ•๋ก 

๋ณธ ์—ฐ๊ตฌ์—์„œ๋Š” ์ •์ฒด๋กœ ์ธํ•ด ์ €์†์œผ๋กœ ์ฃผํ–‰ํ•˜๋Š” ์ฐจ๋Ÿ‰์ด ๋„คํŠธ์›Œํฌ์— ๋ฏธ์น˜๋Š” ์˜ํ–ฅ์„ ๊ณ ๋ คํ•  ์ˆ˜ ์žˆ๋Š” Two-fluid Model์„ ์ œ์•ˆํ•˜๊ณ ์ž ํ•œ๋‹ค. ํŠน์ • ์ž„๊ณ„์†๋„ ์ดํ•˜์˜ ์ฐจ๋Ÿ‰์ด ์ฆ๊ฐ€ํ• ์ˆ˜๋ก ๋„คํŠธ์›Œํฌ์˜ ํ‰๊ท  ์ฃผํ–‰์†๋„๋Š” ๊ฐ์†Œํ•  ๊ฒƒ์ด๋‹ค. ๋”ฐ๋ผ์„œ ๊ธฐ์กด์˜ Two-fluid Model Eq. (1)์„ ๋‹ค์Œ๊ณผ ๊ฐ™์ด ์ ์šฉํ•˜์˜€๋‹ค.

vr=vm(1โˆ’(wfstop+(1โˆ’w)fslow))n(fstop+fslow+ffast=1,fr=fslow+ffast) (9)

(fstop: ์ •์ง€์ฐจ๋Ÿ‰์˜ ๋น„์œจ, fslow: ์ž„๊ณ„์†๋„ ์ดํ•˜ ์ฃผํ–‰์ฐจ๋Ÿ‰์˜ ๋น„์œจ, ffast: ์ž„๊ณ„์†๋„ ์ด์ƒ ์ฃผํ–‰์ฐจ๋Ÿ‰์˜ ๋น„์œจ, w: ๊ฐ€์ค‘์น˜)

vr=1Tm(1โˆ’(wfstop+(1โˆ’w)fslow)n (10)
v=vrร—(fslow+ffast) (11)
v=1T=1Tm(1โˆ’(wffast+(1โˆ’w)fslow))n(fslow+ffast) (12)
or=1Tm(1โˆ’(wffast+(1โˆ’w)fslow))n(fslow+ffast) (13)

Model์˜ ์ ํ•ฉ์„ฑ์„ ํŒ๋‹จํ•˜๊ธฐ ์œ„ํ•ด ๊ฐ ๊ฒฝ๊ณ„์กฐ๊ฑด ๋ณ„ ๋„คํŠธ์›Œํฌ์˜ ํ‰๊ท  ํ†ตํ–‰์†๋„๋ฅผ ์‚ฐ์ •ํ•˜์˜€๋‹ค. ์ •์ง€์ฐจ๋Ÿ‰์˜ ๋น„์œจ์ด 1์ผ ๋•Œ์—๋Š” ํ‰๊ท  ํ†ตํ–‰์†๋„๋Š” 0์œผ๋กœ ๋‚˜ํƒ€๋‚ฌ์œผ๋ฉฐ, ์ž„๊ณ„์†๋„ ์ด์ƒ ์ฃผํ–‰์ฐจ๋Ÿ‰์˜ ๋น„์œจ์ด 1์ผ ๋•Œ ํ‰๊ท  ํ†ตํ–‰์†๋„๋Š” ์ตœ๋Œ€ ์ฃผํ–‰์†๋„๋กœ ๋‚˜ํƒ€๋‚ฌ๋‹ค. ๋˜ํ•œ ์ž„๊ณ„์†๋„ ์ดํ•˜ ์ฃผํ–‰์ฐจ๋Ÿ‰์˜ ๋น„์œจ์ด 1์ผ ๋•Œ ํ‰๊ท  ํ†ตํ–‰์†๋„๋Š” ์ตœ๋Œ€ ์ฃผํ–‰์†๋„๋ณด๋‹ค ๋‚ฎ์€ ๊ฐ’์œผ๋กœ ์‚ฐ์ •๋ ์—ˆ๋‹ค.

ifโ†’f=(fstop,fslow,ffast)=(1,0,0)v=vm(1โˆ’(wfstop+(1โˆ’w)fslow))nร—(fslow+ffast)=vm(1โˆ’(wร—1+(1โˆ’w)ร—0))nร—(0+0)=0 (14)
ifโ†’f=(fstop,fslow,ffast)=(0,1,0)v=vm(1โˆ’(wfstop+(1โˆ’w)fslow))nร—(fslow+ffast)=vm(1โˆ’(wร—0+(1โˆ’w)ร—1))nร—(1+0)=vm(1โˆ’(1โˆ’w))n=vmร—wn (15)
ifโ†’f=(fstop,fslow,ffast)=(0,0,1)v=vm(1โˆ’(wfstop+(1โˆ’w)fslow))nร—(fslow+ffast)=vm(1โˆ’(wร—0+(1โˆ’w)ร—0))nร—(0+1)=vm(1)n=vm (16)

DeMarchi et al.(2010)์€ ํ‰๊ท  ์ œ๊ณฑ๊ทผ ํŽธ์ฐจ(Root Mean Square Error; RMSE) ์ตœ์†Œํ™”๊ฐ€ ์ „์—ญํ•ด(Global Solution)์™€ ๊ฐ€์žฅ ์œ ์‚ฌํ•œ ๊ฒฐ๊ณผ๋ฅผ ๋„์ถœํ•  ์ˆ˜ ์žˆ๋Š” ๋ฐฉ๋ฒ•๋ก ์ž„์„ ๋งํ•˜๊ณ  ์žˆ๋‹ค. ๊ทธ๋ฆฌ๊ณ  Ertem et al.(2018)์— ์˜ํ•˜๋ฉด RMSE ์ตœ์†Œํ™”๋Š” ์‹œ๊ณ„์—ด ๋ถ„์„์—์„œ ๋†’์€ ์ •ํ™•๋„๋ฟ๋งŒ ์•„๋‹ˆ๋ผ, Peak์˜ ์‹œ๊ฐ๊ณผ ํฌ๊ธฐ์˜ ์ถ”์ •์— ๊ฐ€์žฅ ์ ํ•ฉํ•œ ๋ฐฉ๋ฒ•๋ก ์œผ๋กœ ์•Œ๋ ค์ ธ ์žˆ๋‹ค. ๊ตํ†ต๋ถ€๋ฌธ ์ ์šฉ์‚ฌ๋ก€๋กœ๋Š” Tiaprasert et al.(2015)์—์„œ ๋Œ€๊ธฐํ–‰๋ ฌ ์ถ”์ •์— RMSE ์ตœ์†Œํ™”๋ฅผ ์‚ฌ์šฉํ•œ ๋ฐ” ์žˆ๋‹ค. ์ด์— ๋”ฐ๋ผ ๋ณธ ์—ฐ๊ตฌ์—์„œ ๊ตฌํ•˜๊ณ ์ž ํ•˜๋Š” ๊ฐ€์ค‘์น˜์™€ ์ •์ฒดํŒ๋‹จ์˜ ์ž„๊ณ„์†๋„๋Š” ํ‰๊ท  ์ œ๊ณฑ๊ทผ ํŽธ์ฐจ๋ฅผ ์ตœ์†Œํ™”ํ•˜๋Š” ๊ฐ’์œผ๋กœ ์‚ฐ์ •ํ•˜์˜€๋‹ค. ์ •์ฒดํŒ๋‹จ ์†๋„์™€ ๊ฐ€์ค‘์น˜๋ฅผ ๊ตฌํ•˜๊ธฐ ์œ„ํ•œ Model์€ ๋‹ค์Œ๊ณผ ๊ฐ™๋‹ค. Two-fluid Model์—์„œ n์˜ ๊ฐ’์ด 1๋ณด๋‹ค ์ž‘์œผ๋ฉด ์ •์ง€์ฐจ๋Ÿ‰ ๋ฐ ์ €์†์ฐจ๋Ÿ‰์ด ๋Š˜์–ด๋‚จ์— ๋”ฐ๋ผ ์ฃผํ–‰์†๋„๊ฐ€ ์ฆ๊ฐ€ํ•˜๊ฒŒ ๋˜๋ฏ€๋กœ n์— ๋Œ€ํ•œ ์ œ์•ฝ์กฐ๊ฑด์„ ์ถ”๊ฐ€ํ•˜์˜€๊ณ , ๋˜ํ•œ Eq. (16)์œผ๋กœ๋ถ€ํ„ฐ ์ •์ฒดํŒ๋‹จ์˜ ์ž„๊ณ„์†๋„์— ๋Œ€ํ•œ ์ œ์•ฝ์กฐ๊ฑด์„ ์ถ”๊ฐ€ํ•˜์˜€๋‹ค. RMSE๋Š” ์ •์ฒดํŒ๋‹จ์˜ ์ž„๊ณ„์†๋„ ๋ฐ ๊ฐ€์ค‘์น˜์— ์˜ํ•ด ์ •ํ•ด์ง„๋‹ค. ๊ทธ๋Ÿฌ๋‚˜ RMSE๋ฅผ ์ •์ฒดํŒ๋‹จ์˜ ์ž„๊ณ„์†๋„ ๋ฐ ๊ฐ€์ค‘์น˜๋ฅผ ํ†ตํ•ด ์ˆ˜์‹ํ™”ํ•˜๋Š” ์–ด๋ ค์›€์œผ๋กœ ์ธํ•˜์—ฌ, ์ตœ์ ํ•ด๋Š” ์ „์—ญ๊ฒ€์ƒ‰์„ ํ†ตํ•ด ๊ตฌํ•˜์˜€๋‹ค(Fig. 2 ์ฐธ๊ณ ).

minRMSE(w,vc)=โˆšโˆ‘(xtyt)2T (17)

(vc: ์ •์ฒดํŒ๋‹จ์˜ ์ž„๊ณ„์†๋„, xi: ๊ด€์ธก ์ฃผํ–‰์†๋„, yi: Model ์ฃผํ–‰์†๋„, t: ๋‹จ์œ„์‹œ๊ฐ„, T: ์ „์ฒด ๊ด€์ธก์‹œ๊ฐ„)

   s.t.  0 < w <1          0 < vc <vmwn          n > 1

Figure_KSCE_39_1_07_F2.jpg
Fig. 2.

Research Flow Chart

3.4 ์—ฐ๊ตฌ ๋ฒ”์œ„

๋ณธ ์—ฐ๊ตฌ์˜ ๊ณต๊ฐ„์  ๋ฒ”์œ„๋Š” ์„œ์šธํŠน๋ณ„์‹œ 10๊ฐœ ๊ตฌ(๊ฐ•๋‚จ๊ตฌ, ๊ฐ•๋ถ๊ตฌ, ๊ด€์•…๊ตฌ, ๋„๋ด‰๊ตฌ, ๋™๋Œ€๋ฌธ๊ตฌ, ๋™์ž‘๊ตฌ, ์ค‘๊ตฌ, ์ข…๋กœ๊ตฌ, ์šฉ์‚ฐ๊ตฌ, ์€ํ‰๊ตฌ)๋กœ ํ•˜์˜€์œผ๋ฉฐ(Fig. 3 ์ฐธ๊ณ ), ์‹œ๊ฐ„์  ๋ฒ”์œ„๋Š” 2016๋…„ 3์›” 17์ผ(๋ชฉ)์œผ๋กœ ํ•˜์˜€๋‹ค. ๋ถ„์„์— ์‚ฌ์šฉํ•œ ์ž๋ฃŒ๋Š” ์„œ์šธ์‹œ TOPIS์˜ ํƒ์‹œ DTG ์ž๋ฃŒ์ด๋ฉฐ, Two-fluid Model ๋ถ„์„์„ ์œ„ํ•œ ๋‹จ์œ„์‹œ๊ฐ„์€ TOPIS์˜ ์ž๋ฃŒ์ˆ˜์ง‘ ์ฃผ๊ธฐ์™€ ๋™์ผํ•œ 150์ดˆ๋กœ ํ•˜์˜€๋‹ค(๊ตฌ ๋ณ„ ์ด 576๊ฐœ Data Set). TOPIS์—์„œ ์ œ๊ณตํ•˜๋Š” ํƒ์‹œ DTG ์ž๋ฃŒ๋Š” 10์ดˆ ๋‹จ์œ„์˜ ์ˆœ๊ฐ„์†๋„์ด๋ฏ€๋กœ ๋„คํŠธ์›Œํฌ ๋‚ด ์ •์ง€์ฐจ๋Ÿ‰์˜ ๋น„์œจ๊ณผ ํ‰๊ท ์ฃผํ–‰์†๋„๋ฅผ ์ •ํ™•ํžˆ ์‚ฐ์ •ํ•˜๋Š” ๊ฒƒ์— ํ•œ๊ณ„๊ฐ€ ์žˆ์„ ์ˆ˜ ์žˆ๋‹ค. ๊ทธ๋Ÿฌ๋‚˜ ๋ถ„์„์— ์‚ฌ์šฉํ•œ ์ž๋ฃŒ์˜ ํ‘œ๋ณธ์€ 150์ดˆ๋‹น ์ตœ์†Œ 386๊ฐœ์—์„œ ์ตœ๋Œ€ 27,991๊ฐœ๋กœ, ํ‘œ๋ณธ์˜ ์ˆ˜๊ฐ€ ์ถฉ๋ถ„ํ•˜๋ฏ€๋กœ 10์ดˆ ๋‹จ์œ„์˜ ์ž๋ฃŒ๋ฅผ ํ†ตํ•ด์„œ ๋„คํŠธ์›Œํฌ ๋‚ด ์ •์ง€์ฐจ๋Ÿ‰ ๋น„์œจ๊ณผ ํ‰๊ท ์ฃผํ–‰์†๋„๋ฅผ ์ถ”์ •ํ•˜๋Š” ๊ฒƒ์—๋Š” ๋ฌธ์ œ๊ฐ€ ์—†์„ ๊ฒƒ์œผ๋กœ ํŒ๋‹จ๋œ๋‹ค(Table 1 ์ฐธ๊ณ ).

Figure_KSCE_39_1_07_F3.jpg
Fig. 3.

Spatial Scope (Seoul)

Table 1. Number of Data in 150 Second by Region

Region Max Min Average
Dobong-gu 4,089 586 1,868
Dongdaemun-gu 3,135 386 1,669
Dongjak-gu 3,176 446 1,558
Eunpyeong-gu 4,230 683 2,343
Gangbuk-gu 27,991 4,244 14,710
Gangnam-gu 7,615 1,557 4,271
Gwanak-gu 24,304 2,755 13,738
Jongno-gu 14,852 1,275 8,224
Jung-gu 8,995 1,361 5,728
Yongsan-gu 6,266 479 3,858
Average 10,465 1,377 5,797

4. ์—ฐ๊ตฌ๊ฒฐ๊ณผ

Table 2์— ์ œ์‹œ๋œ ๊ฒƒ๊ณผ ๊ฐ™์ด ์„œ์šธ์‹œ 10๊ฐœ ๊ตฌ์— ๋Œ€ํ•ด ๋ถ„์„์„ ์ˆ˜ํ–‰ํ•œ ๊ฒฐ๊ณผ, ์„œ์šธ์‹œ์˜ ์ •์ฒดํŒ๋‹จ์˜ ์ž„๊ณ„์†๋„(vc)๋Š” ์•ฝ 32 kph์—์„œ 38 kph์˜ ๋ฒ”์œ„๋ฅผ ๊ฐ€์ง€๋Š” ๊ฒƒ์œผ๋กœ ๋‚˜ํƒ€๋‚ฌ์œผ๋ฉฐ, ์ •์ง€์ฐจ๋Ÿ‰์— ๋Œ€ํ•œ ๊ฐ€์ค‘์น˜(w)๋Š” ์ตœ์†Œ 0.35์—์„œ ์ตœ๋Œ€ 0.42์˜ ๊ฐ’์„ ๊ฐ€์ง€๋Š” ๊ฒƒ์œผ๋กœ ๋‚˜ํƒ€๋‚ฌ๋‹ค. ๋ณธ ์—ฐ๊ตฌ์—์„œ ์˜๋ฏธํ•˜๋Š” ๋ฐ”๋Š” ์ •์ง€์ฐจ๋Ÿ‰์˜ ๋น„์œจ์€ ๋„คํŠธ์›Œํฌ์˜ ํ‰๊ท ์†๋„์— 0.39 ๋งŒํผ์˜ ์˜ํ–ฅ์„ ๋ฏธ์น˜๋ฉฐ, ์ž„๊ณ„์†๋„ ์ดํ•˜ ์ •์ฒด์ฐจ๋Ÿ‰์˜ ๋น„์œจ์€ 0.61 ๋งŒํผ์˜ ์˜ํ–ฅ์„ ๋ฏธ์นœ๋‹ค๋Š” ๊ฒƒ์ด๋‹ค. ์ •์ง€์ฐจ๋Ÿ‰์ด ์ž„๊ณ„์†๋„ ์ดํ•˜ ์ •์ฒด์ฐจ๋Ÿ‰์— ๋น„ํ•ด ๋„คํŠธ์›Œํฌ์— ๋ฏธ์น˜๋Š” ์˜ํ–ฅ์ด ๋” ์ ์€ ๊ฒƒ์œผ๋กœ ๋‚˜ํƒ€๋‚ฌ๋‹ค. ์ด๋Š” ๋„์‹œ๋ถ€ ๊ฐ€๋กœ๋ง์—๋Š” ์‹ ํ˜ธ๊ต์ฐจ๋กœ์— ์˜ํ•ด ์ •์ง€์ฐจ๋Ÿ‰์ด ํ•ญ์ƒ ํฌํ•จ๋˜์–ด ์žˆ์œผ๋ฏ€๋กœ ์ •์ง€์ฐจ๋Ÿ‰์˜ ๋น„์œจ์ด ๋„คํŠธ์›Œํฌ์— ์ƒ๋Œ€์ ์œผ๋กœ ์˜ํ–ฅ์„ ๋œ ๋ฏธ์น˜๋Š” ๊ฒƒ์œผ๋กœ ํŒ๋‹จ๋œ๋‹ค. ๊ธฐ์กด Model์€ ์ •์ง€์ฐจ๋Ÿ‰๊ณผ ์ฃผํ–‰์ฐจ๋Ÿ‰์œผ๋กœ๋งŒ ๋‚˜๋ˆ„์—ˆ๋Š”๋ฐ, ๋ณธ ์—ฐ๊ตฌ๊ฒฐ๊ณผ๋ฅผ ํ†ตํ•ด ์ •์ฒด๋กœ ์ธํ•œ ์ €์†์ฐจ๋Ÿ‰๋„ ์ •์ง€์ฐจ๋Ÿ‰๋งŒํผ ๋„คํŠธ์›Œํฌ ์„ฑ๋Šฅ์— ์˜ํ–ฅ์„ ๋ฏธ์นœ๋‹ค๋Š” ๊ฒƒ์„ ์•Œ ์ˆ˜ ์žˆ์—ˆ๋‹ค. Two-fluid Model์˜ ํŒŒ๋ผ๋ฏธํ„ฐ์ธ Tm์€ ๊ธฐ์กด Model์—์„œ ํ‰๊ท  0.76์ด์—ˆ๊ณ  ๋ณธ ์—ฐ๊ตฌ์—์„œ ์ œ์•ˆํ•œ Model์€ ํ‰๊ท  0.72๋กœ ํฐ ๋ณ€ํ™”๋ฅผ ๋ณด์ด์ง€ ์•Š์•˜๋‹ค. ๋งˆ์ฐฌ๊ฐ€์ง€๋กœ n์˜ ํ‰๊ท  ์—ญ์‹œ ๊ธฐ์กด Model๊ณผ ๋ณธ ์—ฐ๊ตฌ์—์„œ ์ œ์•ˆํ•œ Model์˜ ๊ฐ’์ด ๊ฐ๊ฐ 2.39์™€ 2.26์œผ๋กœ ํฐ ์ฐจ์ด๋ฅผ ๋ณด์ด์ง€ ์•Š์•˜๋‹ค. ๊ฐ Model ์ ํ•ฉ์„ฑ์„ ํŒ๋‹จํ•  ์ˆ˜ ์žˆ๋Š” ๊ฒฐ์ •๊ณ„์ˆ˜(R2)๋Š” ๋ชจ๋“  ์ง€์—ญ์—์„œ ์ฆ๊ฐ€ํ•œ ๊ฒƒ์„ ์•Œ ์ˆ˜ ์žˆ์œผ๋ฉฐ, 10๊ฐœ ๊ตฌ์˜ ๊ฒฐ์ •๊ณ„์ˆ˜๋Š” ํ‰๊ท  0.78์—์„œ ํ‰๊ท  0.99๋กœ ์ ํ•ฉ์„ฑ์ด ์ฆ๊ฐ€ํ•œ ๊ฒƒ์„ ํ™•์ธํ•˜์˜€๋‹ค. Fig. 4์˜ ๋„๋ด‰๊ตฌ(a), ๋™๋Œ€๋ฌธ๊ตฌ(b), ์€ํ‰๊ตฌ(d) ๋“ฑ์˜ ์ง€์—ญ์€ ๊ธฐ์กด Model์—์„œ ์ฃผํ–‰์†๋„์™€ ์ •์ง€์ฐจ๋Ÿ‰ ๋น„์œจ์˜ ์„ ํ˜•๊ด€๊ณ„๋ฅผ ์ฐพ๊ธฐ ์–ด๋ ต๊ณ , ์ ํ•ฉ๋„ ์—ญ์‹œ ๋‚ฎ์€ ๊ฐ’์„ ๊ฐ€์กŒ๋‹ค. ๋ฐ˜๋ฉด ๋ณธ ์—ฐ๊ตฌ์—์„œ ์ œ์•ˆํ•œ Model์€ ์ด๋Ÿฌํ•œ ์ง€์—ญ์—์„œ๋„ ๋†’์€ ์ ํ•ฉ๋„๋ฅผ ๊ฐ€์ง€๋Š” ๊ฒƒ์œผ๋กœ ๋‚˜ํƒ€๋‚ฌ๋‹ค.

Table 2. Two-fluid Parameters by Regions

Region Tm (min/km) n R2 Congestion speed (km/h) w
Original Proposed Original Proposed Original Proposed
Dobong-gu 0.77 0.76 2.35 2.06 0.56 0.99 35 0.37
Dongdaemun-gu 0.96 0.75 1.78 2.11 0.67 0.99 35 0.37
Dongjak-gu 0.96 0.80 2.37 2.17 0.69 0.98 32 0.42
Eunpyeong-gu 0.73 0.74 2.54 2.09 0.68 0.99 36 0.40
Gangbuk-gu 0.75 0.78 2.55 1.97 0.78 0.99 35 0.37
Gangnam-gu 0.80 0.62 1.97 2.71 0.94 0.99 32 0.40
Gwanak-gu 0.62 0.65 2.67 2.32 0.94 1.00 35 0.37
Jongno-gu 0.68 0.78 2.59 2.23 0.90 1.00 32 0.41
Jung-gu 0.60 0.70 2.57 2.69 0.90 1.00 29 0.35
Yongsan-gu 0.68 0.64 2.53 2.26 0.78 0.99 38 0.40
Average 0.76 0.72 2.39 2.26 0.78 0.99 33.9 0.39

Figure_KSCE_39_1_07_F4.jpg
Fig. 4.

Two-Fluid Model Parameters Diagram by Region (Left: Original Model, Right: Proposed Model)

5. ๊ฒฐ ๋ก 

๊ธฐ์กด์˜ Two-fluid Model์€ ๋„คํŠธ์›Œํฌ์˜ ์ฐจ๋Ÿ‰์„ ์ •์ง€์ฐจ๋Ÿ‰๊ณผ ์ฃผํ–‰์ฐจ๋Ÿ‰์˜ ๋‘ ๊ฐ€์ง€๋กœ ๊ตฌ๋ถ„ํ•˜์—ฌ ๋„คํŠธ์›Œํฌ์˜ ๋ถ„์„์„ ์ง„ํ–‰ํ•˜์˜€๋‹ค. ๋„คํŠธ์›Œํฌ ๋‚ด ๊ตํ†ต์ˆ˜์š”๊ฐ€ ์ฆ๊ฐ€ํ•˜๋ฉด, ์ •์ง€์ฐจ๋Ÿ‰๋ฟ๋งŒ ์•„๋‹ˆ๋ผ ์ •์ฒด๋กœ ์ธํ•œ ์ €์†์ฐจ๋Ÿ‰์˜ ๋น„์œจ๋„ ์ฆ๊ฐ€ํ•˜๊ฒŒ ๋œ๋‹ค. ๋”ฐ๋ผ์„œ ๋ณธ ์—ฐ๊ตฌ์—์„œ๋Š”, ์ œ์•ˆํ•œ Two-fluid Model์„ ํ†ตํ•ด ๋„คํŠธ์›Œํฌ์˜ ํ‰๊ท  ์ฃผํ–‰์†๋„์™€ ์ •์ง€์ฐจ๋Ÿ‰, ์ •์ฒด๋กœ ์ธํ•œ ์ €์†์ฐจ๋Ÿ‰์˜ ๊ด€๊ณ„๋ฅผ ๋ถ„์„ํ•˜์˜€๋‹ค. ๋ถ„์„๊ฒฐ๊ณผ ์ •์ง€์ฐจ๋Ÿ‰๊ณผ ์ •์ฒด๋กœ ์ธํ•œ ์ €์†์ฐจ๋Ÿ‰ ๋ชจ๋‘ ๋„คํŠธ์›Œํฌ์˜ ํ‰๊ท ์†๋„์— ์•…์˜ํ–ฅ์„ ๋ฏธ์น˜๋Š” ๊ฒƒ์œผ๋กœ ๋‚˜ํƒ€๋‚ฌ๋‹ค. ์„œ์šธ์‹œ 10๊ฐœ ๊ตฌ์— ๋Œ€ํ•˜์—ฌ ๊ธฐ์กด Two-fluid Model์˜ ํŒŒ๋ผ๋ฏธํ„ฐ์™€ ๋ณธ ์—ฐ๊ตฌ์—์„œ ์ œ์•ˆํ•œ Model์˜ ํŒŒ๋ผ๋ฏธํ„ฐ๋ฅผ ๊ฐ๊ฐ ์‚ฐ์ •ํ•˜์˜€๋‹ค. Model ๊ฐ„ ํŒŒ๋ผ๋ฏธํ„ฐ๋ฅผ ๋น„๊ตํ•œ ๊ฒฐ๊ณผ, 10๊ฐœ ๊ตฌ์—์„œ Two-fluid Model ํŒŒ๋ผ๋ฏธํ„ฐ Tm๊ณผ n์˜ ํ‰๊ท ๊ฐ’์€ ํฌ๊ฒŒ ์ฐจ์ด๊ฐ€ ์—†์Œ์„ ํ™•์ธํ•˜์˜€๊ณ , ๊ฐ€์ค‘์น˜์™€ ์ •์ฒดํŒ๋‹จ์˜ ์ž„๊ณ„์†๋„๋Š” ๊ตฌ ๋ณ„๋กœ ํฐ ํŽธ์ฐจ๋ฅผ ๋ณด์ด์ง€ ์•Š์•˜๋‹ค. ์ด๋Š” ๋ณธ ์—ฐ๊ตฌ์—์„œ ์ œ์‹œํ•œ Model์ด ๊ธฐ์กด Two-fluid Model๊ณผ ๊ฐ™์ด ๋„คํŠธ์›Œํฌ ๋ฐ ์‹ ํ˜ธ์šด์˜์„ ํ‰๊ฐ€ํ•˜๋Š”๋ฐ ์‚ฌ์šฉ๋  ๊ฐ€๋Šฅ์„ฑ์ด ์žˆ์Œ์„ ์˜๋ฏธํ•œ๋‹ค. ๋˜ํ•œ ๋„คํŠธ์›Œํฌ ๋ฐ ์‹ ํ˜ธ์šด์˜์„ ํ‰๊ฐ€ํ•˜๋Š”๋ฐ ์žˆ์–ด์„œ๋Š” ์ ํ•ฉ๋„๊ฐ€ ๋†’์€ Model์„ ์‚ฌ์šฉํ•˜๋Š” ๊ฒƒ์ด ๋” ํ•ฉ๋ฆฌ์ ์ผ ์ˆ˜ ์žˆ๋‹ค. ๋ณธ ์—ฐ๊ตฌ์—์„œ๋Š” ์ •์ง€์ฐจ๋Ÿ‰๊ณผ ์ •์ฒด๋กœ ์ธํ•œ ์ €์†์ฐจ๋Ÿ‰๋งŒ์„ ๊ณ ๋ คํ•˜์—ฌ ๋„คํŠธ์›Œํฌ ๋ถ„์„์„ ์ง„ํ–‰ํ•˜์˜€์œผ๋‚˜, ํ–ฅํ›„์—๋Š” ๊ตํ†ต๊ณตํ•™์  ์ธก๋ฉด์˜ ์ ‘๊ทผ๋ฐฉ๋ฒ•์ด ์š”๊ตฌ๋  ๊ฒƒ์ด๋‹ค. ์ด์— ๋Œ€ํ•œ ๋ฐฉ์•ˆ์œผ๋กœ๋Š” ์ •์ง€์ฐจ๋Ÿ‰์˜ w์™€ vc์— ๋Œ€ํ•œ ๊ฐ’์„ ๋‹จ์ผ ๊ฐ’์œผ๋กœ ์ œ์‹œํ•˜์ง€ ์•Š๊ณ , ํ†ตํ–‰์†๋„์— ๋Œ€ํ•œ ๊ฐ€์ค‘์น˜๋ฅผ ๋‹จ์ผ ๊ฐ’์ด ์•„๋‹Œ ์†๋„์— ๋Œ€ํ•œ ๋ถ„ํฌ๋กœ ํ‘œํ˜„ํ•œ Model์„ ๊ฐœ๋ฐœํ•˜๋Š” ์—ฐ๊ตฌ๊ฐ€ ๋Œ€ํ‘œ์ ์ผ ๊ฒƒ์ด๋‹ค.

Acknowledgements

์ด ๋…ผ๋ฌธ์€ ๋ฏธ๋ž˜์ฐฝ์กฐ๊ณผํ•™๋ถ€ ์žฌ์›์œผ๋กœ ๊ฒฝ์ฐฐ์ฒญ๊ณผ ์น˜์•ˆ๊ณผํ•™๊ธฐ์ˆ ์—ฐ๊ตฌ๊ฐœ๋ฐœ์‚ฌ์—…๋‹จ์˜ ์ง€์›์„ ๋ฐ›์•„ ์ˆ˜ํ–‰๋œ ์น˜์•ˆ๊ณผํ•™๊ธฐ์ˆ ์—ฐ๊ตฌ๊ฐœ๋ฐœ์‚ฌ์—…์ž„(PA-A000001). ๊ทธ๋ฆฌ๊ณ  ์„œ์šธ๋Œ€ํ•™๊ต ๊ฑด์„คํ™˜๊ฒฝ์ข…ํ•ฉ์—ฐ๊ตฌ์†Œ์˜ ์ง€์›์—๋„ ๊ฐ์‚ฌ๋ฅผ ๋“œ๋ฆฝ๋‹ˆ๋‹ค.

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